UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 8-K

CURRENT REPORT
Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) December 27, 2004

STRUCTURED ASSET SECURITIES CORPORATION (as Depositor under the Trust Agreement, dated as of October 1, 2004, providing for the issuance of Mortgage Pass-Through Certificates, Series 2004-20)
(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction
of incorporation)

333-115858
(Commission
File Number)

74-2440850
(IRS Employer
Identification No.)

745 Seventh Avenue, 7th Floor, New York, NY
(Address of principal executive offices)

10019
(Zip Code)

Registrant's telephone number, including area code 212-526-7000

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

[ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Section 8 - Other Events

Item 8.01. Other Events.

This current report on Form 8-K relates to the monthly distribution reported to the holders of Structured Asset Securities Corporation, Mortgage Pass-Through Certificates, Series 2004-20, which was made on December 27, 2004.

Section 9 - Financial Statements and Exhibits

Item 9.01 Financial Statements and Exhibits.

99.1 Monthly distribution report pursuant to Section 4.03 of the Trust Agreement for the distribution on December 27, 2004.

(Exhibit No. Description)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

LASALLE BANK NATIONAL ASSOCIATION, IN ITS CAPACITY AS TRUSTEE UNDER THE TRUST AGREEMENT ON BEHALF OF STRUCTURED ASSET SECURITIES CORPORATION, REGISTRANT

By: /s/ Russell Goldenberg
Russell Goldenberg
Group Senior Vice President

Date: December 29, 2004

Structured Asset Securities Corporation

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Reporting Package Table of Contents

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Administrator:

Megan Olson 312.904.6709
megan.olson@abnamro.com

Analyst:

Christine Paidosh 714.259.6207
christine.paidosh@abnamro.com

Statement Date:

135 S. LaSalle Street, Suite 1625
Chicago, IL 60603
USA

Statements to Certificateholders
Cash Reconciliation Summary
Bond Interest Reconciliation
Other Related Information

Asset-Backed Facts ~ 15 Month Loan Status Summary

Asset-Backed Facts ~ 15 Month Loan Payoff/Loss Summary
Modified Loan Detail

Realized Loss Detail
Historical REO Report

Page 2-5
Page 6-14
Page 15-16
Page 17

Page 18-26

Page 27-35
Page 36

Page 37
Page 38

Page(s)

Information is available for this issue from the following sources

Issue Id:

Monthly Data File
Name:

SASC0420

SASC0420_200412_3.ZIP

Closing Date:

First Payment Date:

Rated Final Payment: Date:

29-Oct-04
26-Nov-04

25-Nov-34

Parties to The Transaction

Depositor: Structured Asset Securities Corporation

Underwriter: Lehman Brothers Inc.

Master Servicer: Aurora Loan Services, Inc.

Rating Agency: Fitch Ratings/Standard & Poor's

800.246.5761

LaSalle Factor Line

LaSalle Web Site

Servicer Web Site

www.alservices.com

www.etrustee.net

Page 1 of 38

Class

CUSIP

Original

Opening

Principal

Negative

Closing

Interest

Pass-Through

Per $ 1000

Next Rate(3)

WAC:
WAMM:
Current Index:

Payment Date:
Prior Payment:
Next Payment:
Record Date:

6.005376%

2.180000%

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Structured Asset Securities Corporation

Mortgage Pass-Through Certificates

Series 2004-20

Face Value (1)

Balance

Payment

Adj. or Loss

Amortization

Balance

Payment (2)

Adjustment

Rate

354

REMIC III

Statement Date:

ABN AMRO Acct: 722144.1

999.000496400

1.024313200

0.000000000

997.976183200

4.370627200

Fixed

0.00

0.000000000

5.25000000%

0.000000000

86359BH20

1-A1

25,000,000.00

24,975,012.41

25,607.83

0.00

24,949,404.58

109,265.68

1000.000000000

0.000000000

1000.000000000

4.375000000

Fixed

0.00

0.000000000

5.25000000%

0.000000000

86359BH38

1-A2

1,822,000.00

0.00

1,822,000.00

7,971.25

998.579611954

1.451758630

0.000000000

997.127853324

4.368785739

Fixed

0.00

0.000000000

5.25000000%

0.000000000

86359BH46

1-A3

68,832,000.00

68,734,231.85

99,927.45

0.00

68,634,304.40

300,712.26

1000.000000000

0.000000000

1000.000000000

4.375000000

Fixed

0.00

0.000000000

5.25000000%

0.000000000

86359BH53

1-A4

19,082,000.00

0.00

19,082,000.00

83,483.75

1004.375000000

0.000000000

1008.769140468

0.000000000

Fixed

13,138.48

0.00

0.000000000

5.25000000%

4.394140468

86359BH61

1-A5

2,990,000.00

3,003,081.25

0.00

3,016,219.73

0.00

987.574620629

9.024747464

0.000000000

978.549873165

4.526383619

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BH79

2-A1

66,149,000.00

65,327,073.58

596,978.02

0.00

64,730,095.56

299,415.75

994.853168926

11.256381917

0.000000000

983.596787009

4.767004768

Fixed

0.00

0.000000000

5.75000000%

0.000000000

86359BH87

3-A1

85,783,000.00

85,341,489.39

965,606.21

0.00

84,375,883.18

408,927.97

986.430260096

20.705406882

0.000000000

965.724853214

4.932151315

Fixed

0.00

0.000000000

6.00000000%

0.000000000

86359BH95

4-A1

116,803,000.00

115,218,013.67

2,418,453.64

0.00

112,799,560.03

576,090.07

994.279999075

52.664744159

0.000000000

941.615254916

5.178541705

Fixed

0.00

0.000000000

6.25000000%

0.000000000

86359BJ28

5-A1

32,442,000.00

32,256,431.73

1,708,549.63

0.00

30,547,882.10

168,002.25

994.279998800

52.664744000

0.000000000

941.615254800

5.178541600

Fixed

0.00

0.000000000

6.25000000%

0.000000000

86359BJ36

5-A2

25,000,000.00

24,856,999.97

1,316,618.60

0.00

23,540,381.37

129,463.54

994.280000000

52.664748768

0.000000000

941.615251232

5.178541872

Fixed

0.00

0.000000000

6.25000000%

0.000000000

86359BJ44

5-A3

1,015,000.00

1,009,194.20

53,454.72

0.00

955,739.48

5,256.22

992.066143802

0.362599627

0.000000000

991.703544175

4.133609180

Fixed

0.00

0.000000000

5.00000000%

0.000000000

86359BJ51

6-A1

17,691,000.00

17,550,642.15

6,414.75

0.00

17,544,227.40

73,127.68

993.797908933

5.705017057

0.000000000

988.092891876

4.347865857

Fixed

0.00

0.000000000

5.25000000%

0.000000000

86359BJ69

7-A1

34,590,000.00

34,375,469.67

197,336.54

0.00

34,178,133.13

150,392.68

982.211367200

15.863538500

0.000000000

966.347828700

4.297174700

Fixed

0.00

0.000000000

5.25000000%

0.000000000

86359BJ77

8-A1

100,000,000.00

98,221,136.72

1,586,353.85

0.00

96,634,782.87

429,717.47

1000.000000000

0.000000000

1000.000000000

4.375000000

Fixed

0.00

0.000000000

5.25000000%

0.000000000

86359BJ85

8-A2

5,906,000.00

0.00

5,906,000.00

25,838.75

983.203375813

14.978885492

0.000000000

968.224490321

4.096680809

Fixed

0.00

0.000000000

5.00000000%

0.000000000

86359BJ93

8-A3

64,109,000.00

63,032,185.22

960,281.37

0.00

62,071,903.85

262,634.11

Page 2 of 38

Notes: (1) N denotes notional balance not included in total (2) Accrued Interest Plus/Minus Interest Adjustment Minus Deferred Interest equals Interest Payment (3) Estimated. * Denotes Controlling Class

Class

CUSIP

Original

Opening

Principal

Negative

Closing

Interest

Pass-Through

Per $ 1000

Next Rate(3)

WAC:
WAMM:
Current Index:

Payment Date:
Prior Payment:
Next Payment:
Record Date:

6.005376%

2.180000%

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Structured Asset Securities Corporation

Mortgage Pass-Through Certificates

Series 2004-20

Face Value (1)

Balance

Payment

Adj. or Loss

Amortization

Balance

Payment (2)

Adjustment

Rate

354

REMIC III

Statement Date:

ABN AMRO Acct: 722144.1

983.203375827

14.978885579

0.000000000

968.224490248

2.113887311

0.400000000%

0.00

0.000000000

2.58000000%

0.000000000

86359BK26

8-A4

57,734,000.00

56,764,263.70

864,790.98

0.00

55,899,472.72

122,043.17

983.203375827

0.000000000

968.224490248

4.031133821

7.100000000%

0.00

0.000000000

4.92000000%

0.000000000

86359BK34

8-A5

57,734,000.00

56,764,263.70

0.00

55,899,472.72

232,733.48

1000.000000000

0.000000000

1000.000000000

4.791667012

Fixed

0.00

0.000000000

5.75000000%

0.000000000

86359BK42

8-A6

9,664,000.00

0.00

9,664,000.00

46,306.67

1000.000000000

0.000000000

1000.000000000

4.791666781

Fixed

0.00

0.000000000

5.75000000%

0.000000000

86359BK59

8-A7

29,044,000.00

0.00

29,044,000.00

139,169.17

999.065493872

0.845035360

0.000000000

998.220458513

0.000000000

N/A

0.00

0.000000000

0.00000000%

0.000000000

86359BK67

2,739,554.00

2,736,993.87

2,315.02

0.00

2,734,678.85

0.00

976.921951264

0.000000000

962.262193550

4.477558634

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BK75

AX(1,8)

5,669,842.00

5,538,993.11

0.00

5,455,874.60

25,387.05

987.644971391

0.000000000

937.512359781

4.526704886

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BK83

AX(2-7)

3,234,483.00

3,194,520.87

0.00

3,032,367.79

14,641.55

999.259903410

0.000000000

990.214568566

4.579941047

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BK91

PAX(1,8)

2,355,098.00

2,353,355.00

0.00

2,332,052.35

10,786.21

999.090705315

0.000000000

992.592770729

4.579167814

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BL25

PAX(2-7)

1,561,430.00

1,560,010.20

0.00

1,549,864.13

7,150.05

999.675281867

0.318625559

0.000000000

999.356656308

4.737913532

5.687382417%

0.00

0.000000000

5.68734315%

0.000000000

86359BL33

18,342,000.00

18,336,044.02

5,844.23

0.00

18,330,199.79

86,902.81

999.675281087

0.318624869

0.000000000

999.356656217

4.737914316

5.687382417%

0.00

0.000000000

5.68734315%

0.000000000

86359BL41

4,785,000.00

4,783,446.22

1,524.62

0.00

4,781,921.60

22,670.92

999.675281261

0.318624149

0.000000000

999.356657112

4.737914726

5.687382417%

0.00

0.000000000

5.68734315%

0.000000000

86359BL58

2,791,000.00

2,790,093.71

889.28

0.00

2,789,204.43

13,223.52

999.675280100

0.318624582

0.000000000

999.356655518

4.737913880

5.687382417%

0.00

0.000000000

5.68734315%

0.000000000

86359BG70/U85985SU1

2,392,000.00

2,391,223.27

762.15

0.00

2,390,461.12

11,333.09

999.675278997

0.318626959

0.000000000

999.356652038

4.737912226

5.687382417%

0.00

0.000000000

5.68734315%

0.000000000

86359BG88/U85985SV9

1,595,000.00

1,594,482.07

508.21

0.00

1,593,973.86

7,556.97

999.675283358

0.318628205

0.000000000

999.356655152

4.737910252

5.687382417%

0.00

0.000000000

5.68734315%

0.000000000

86359BG96/U85985SW7

1,202,279.00

1,201,888.60

383.08

0.00

1,201,505.52

5,696.29

0.000000000

Fixed

0.00

0.000000000

N/A

0.000000000

86359BL66

100.00

0.00

Page 3 of 38

Class

CUSIP

Original

Opening

Principal

Negative

Closing

Interest

Pass-Through

Per $ 1000

Next Rate(3)

WAC:
WAMM:
Current Index:

Payment Date:
Prior Payment:
Next Payment:
Record Date:

6.005376%

2.180000%

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Structured Asset Securities Corporation

Mortgage Pass-Through Certificates

Series 2004-20

Face Value (1)

Balance

Payment

Adj. or Loss

Amortization

Balance

Payment (2)

Adjustment

Rate

354

REMIC III

Statement Date:

ABN AMRO Acct: 722144.1

0.000000000

0.00

0.000000000

N/A

0.000000000

9ABSS827

R-I

0.00

0.000000000

0.00

0.000000000

N/A

0.000000000

9ABSS828

R-II

0.00

Total P&I Payment

13,138.48

0.00

797,502,933.00

790,017,397.27

14,588,500.56

Total

779,217,935.57

10,812,600.18

0.00

3,775,900.38

Page 4 of 38

Class

CUSIP

Original

Opening

Principal

Negative

Closing

Interest

Pass-Through

Per $ 1000

Next Rate(3)

WAC:
WAMM:
Current Index:

Payment Date:
Prior Payment:
Next Payment:
Record Date:

6.005376%

2.180000%

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Structured Asset Securities Corporation

Mortgage Pass-Through Certificates

Series 2004-20

Face Value (1)

Balance

Payment

Adj. or Loss

Amortization

Balance

Payment (2)

Adjustment

Rate

354

Grantor Trust

Statement Date:

ABN AMRO Acct: 722144.1

0.000000000

0.00

7,555.80

0.000000000

N/A

0.000000000

9ABSS861

0.00

7,555.80

0.000000000

0.00

0.000000000

N/A

0.000000000

9ABSS862

0.00

Total P&I Payment

0.00

7,555.80

0.00

7,555.80

Total

0.00

7,555.80

Page 5 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

1,136,712.16

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

3,835,982.44

Unscheduled Interest:
Prepayment Penalties

7,555.80

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

7,555.80

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Scheduled Principal:
Current Scheduled Principal
Advanced Scheduled Principal
Scheduled Principal
Unscheduled Principal:
Curtailments
Prepayments in Full
Liquidation Proceeds
Repurchase Proceeds
Other Principal Proceeds
Total Unscheduled Principal
Remittance Principal

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

3,796,594.86

0.00
0.00
0.00
0.00

0.00

57,369.59

194,990.56
252,360.15

1,063,162.06
9,483,939.49

0.00
0.00
0.00

10,547,101.55
10,799,461.70

14,596,056.56

790,017,398.09

2,562

252,360.15

10,547,101.55

0.00
0.00

0.00

779,217,936.39

2,530

193,389.78

3,113,919.99

194,990.56

2,699,270.28

197,488.30

2,745,675.69

46,943.37

0.00
0.00

117,643.58

164,586.96

5,459.66

)

(5,459.66

0.00
0.00
0.00
0.00

0.00

)

(46,943.37

3,796,594.86

Interest Not Advanced (

Current Period

)

0.00

2,699,270.28

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(3,067,514.57

)

(190,892.04

0.00

Advance Summary (Advance Made by Servicer)

Page 6 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 1

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

134,819.74

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

550,201.90

Unscheduled Interest:
Prepayment Penalties

0.00

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

0.00

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

544,162.15

0.00
0.00
0.00
0.00

0.00

19,881.72
74,755.63
94,637.35

21,986.79

0.00
0.00
0.00
0.00

21,986.79

116,624.14

660,786.29

122,883,907.18

217

94,637.35
21,986.79

0.00
0.00

0.00

122,767,283.04

217

78,631.66

470,779.40

74,755.63

415,382.16

76,715.41

422,996.12

6,039.75

0.00
0.00

19,561.06

25,600.81

0.00
0.00
0.00
0.00
0.00
0.00

0.00

)

(6,039.75

544,162.15

Interest Not Advanced (

Current Period

)

0.00

415,382.16

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(463,165.44

)

(76,671.88

0.00

Advance Summary (Advance Made by Servicer)

Page 7 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 2

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

107,177.82

0.00

)

(1,029.23

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

319,920.33

Unscheduled Interest:
Prepayment Penalties

0.00

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

0.00

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

316,357.19

0.00
0.00
0.00
0.00

0.00

0.00
0.00
0.00

26,197.28

570,780.74

0.00
0.00
0.00

596,978.02
596,978.02

913,335.21

68,012,426.09

310

0.00

596,978.02

0.00
0.00

0.00

67,415,448.07

307

2,172.73

271,366.69

0.00

213,771.74

8.43

219,807.10

4,592.37

0.00

)

(1,029.23

9,576.88

13,140.02

1,029.23

0.00
0.00
0.00

1,029.23
1,029.23

0.00

)

(3,563.14

316,357.19

Interest Not Advanced (

Current Period

)

0.00

213,771.74

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(265,331.32

)

(2,164.30

0.00

Advance Summary (Advance Made by Servicer)

Page 8 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 3

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

151,940.71

0.00

)

(629.65

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

436,356.86

Unscheduled Interest:
Prepayment Penalties

7,555.80

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

7,555.80

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

438,282.61

0.00
0.00
0.00
0.00

0.00

0.00
0.00
0.00

106,038.70
859,567.51

0.00
0.00
0.00

965,606.21
965,606.21

1,403,888.82

88,823,179.52

402

0.00

965,606.21

0.00
0.00

0.00

87,857,573.31

398

420.04

362,571.61

0.00

285,045.80

4.62

291,186.61

6,259.70

0.00

)

(629.65

12,245.12

17,875.18

1,053.07

)

(423.42

0.00
0.00

629.65
629.65

0.00

)

(5,630.05

438,282.61

Interest Not Advanced (

Current Period

)

0.00

285,045.80

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(356,430.80

)

(415.42

0.00

Advance Summary (Advance Made by Servicer)

Page 9 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 4

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

212,053.76

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

614,406.48

Unscheduled Interest:
Prepayment Penalties

0.00

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

0.00

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

606,016.11

0.00
0.00
0.00
0.00

0.00

0.00
0.00
0.00

515,256.45

1,903,197.19

0.00
0.00
0.00

2,418,453.64
2,418,453.64

3,024,469.75

119,959,016.46

581

0.00

2,418,453.64

0.00
0.00

0.00

117,540,562.82

573

1,367.77

510,822.63

0.00

402,352.71

9.61

409,838.50

8,390.36

0.00
0.00

16,601.10

24,991.46

447.48

)

(447.48

0.00
0.00
0.00
0.00

0.00

)

(8,390.36

606,016.11

Interest Not Advanced (

Current Period

)

0.00

402,352.71

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(503,336.85

)

(1,358.16

0.00

Advance Summary (Advance Made by Servicer)

Page 10 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 5

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

126,448.80

0.00

)

(905.04

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

322,223.41

Unscheduled Interest:
Prepayment Penalties

0.00

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

0.00

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

318,316.30

0.00
0.00
0.00
0.00

0.00

102.89

0.00

102.89

24,105.24

3,054,418.85

0.00
0.00
0.00

3,078,524.09
3,078,626.98

3,396,943.28

60,494,900.37

320

102.89

3,078,524.09

0.00
0.00

0.00

57,416,273.39

308

3,079.26

266,990.36

0.00

196,679.66

0.44

201,318.06

4,812.15

0.00

)

(905.04

7,790.95

11,698.06

2,558.59

)

(1,653.55

0.00
0.00

905.04
905.04

0.00

)

(3,907.11

318,316.30

Interest Not Advanced (

Current Period

)

0.00

196,679.66

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(262,351.96

)

(3,078.82

0.00

Advance Summary (Advance Made by Servicer)

Page 11 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 6

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

15,621.06

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

77,648.20

Unscheduled Interest:
Prepayment Penalties

0.00

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

0.00

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

76,898.03

0.00
0.00
0.00
0.00

0.00

0.00
0.00
0.00

6,481.58

0.00
0.00
0.00
0.00

6,481.58
6,481.58

83,379.61

18,629,239.21

0.00

6,481.58

0.00
0.00

0.00

18,622,757.63

156.68

71,798.22

0.00

62,027.14

0.00

62,027.14

750.17

0.00
0.00

3,130.92

3,881.09

0.00
0.00
0.00
0.00
0.00
0.00

0.00

)

(750.17

76,898.03

Interest Not Advanced (

Current Period

)

0.00

62,027.14

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(71,798.22

)

(156.68

0.00

Advance Summary (Advance Made by Servicer)

Page 12 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 7

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

52,803.45

0.00

)

(371.28

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

160,402.17

Unscheduled Interest:
Prepayment Penalties

0.00

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

0.00

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

158,401.14

0.00
0.00
0.00
0.00

0.00

0.00
0.00
0.00

10,397.85

186,938.69

0.00
0.00
0.00

197,336.54
197,336.54

355,737.68

35,780,235.94

174

0.00

197,336.54

0.00
0.00

0.00

35,582,899.40

173

232.24

141,072.66

0.00

107,970.00

0.00

107,970.00

2,372.31

0.00

)

(371.28

5,081.90

7,082.93

371.28

0.00
0.00
0.00

371.28
371.28

0.00

)

(2,001.03

158,401.14

Interest Not Advanced (

Current Period

)

0.00

107,970.00

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(141,072.66

)

(232.24

0.00

Advance Summary (Advance Made by Servicer)

Page 13 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Cash Reconciliation Summary Pool Group 8

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

335,846.81

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

1,351,887.88

Unscheduled Interest:
Prepayment Penalties

0.00

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

0.00

Less Fees & Expenses Paid By/To Servicer

Less Fee Paid To Servicer
Less Fee Strips Paid by Servicer

Special Servicing Fees

Interest Due Serv on Advances
Recoup of Prior Advances
Misc. Fees & Expenses

Total Unscheduled Fees & Expenses

Total Interest Due Trust

Less Fees & Expenses Paid By/To Trust
Trustee Fee
Fee Strips
Misc. Fees
Interest Reserve Withholding
Plus Interest Reserve Deposit
Total

Total Interest Due Certs

Principal Summary

Remittance P&I Due Trust

Remittance P&I Due Certs

Pool Balance Summary

Beginning Pool
Scheduled Principal
Unscheduled Principal
Deferred Interest
Liquidations
Repurchases

Ending Pool

Balance

Count

Principal

Interest

Prior Outstanding

Plus Current Period

Less Recovered

Ending Outstanding

Servicing Fee Summary

Current Servicing Fees
Plus Fees Advanced for PPIS
Less Reduction for PPIS
Plus Delinquent Servicing Fees

Total Servicing Fees

PPIS Summary

Gross PPIS
Reduced by PPIE
Reduced by Shortfalls in Fees
Reduced by Other Amounts
PPIS Reducing Scheduled Interest
PPIS Reducing Servicing Fee

PPIS Due Certificate

0.00

0.00
0.00

0.00

1,338,161.33

0.00
0.00
0.00
0.00

0.00

37,384.98

120,234.93
157,619.91

352,698.17

2,909,036.51

0.00
0.00
0.00

3,261,734.68
3,419,354.59

4,757,515.92

275,434,493.32

471

157,619.91

3,261,734.68

0.00
0.00

0.00

272,015,138.73

467

107,329.40

1,018,518.43

120,234.93

1,016,041.06

120,749.79

1,030,532.16

13,726.55

0.00
0.00

43,655.63

57,382.19

0.00
0.00
0.00
0.00
0.00
0.00

0.00

)

(13,726.55

1,338,161.33

Interest Not Advanced (

Current Period

)

0.00

1,016,041.06

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(1,004,027.33

)

(106,814.54

0.00

Advance Summary (Advance Made by Servicer)

Page 14 of 38

Structured Asset Securities Corporation

Class

Accrued

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1
Bond Interest Reconciliation

Deductions

Allocable

Deferred &

Prior

Prepay-

Other

Additions

Interest

Credit Support

Original

Current(4)

Accrual

Int. Short-

falls Due

ment

Interest

Interest (2)

Payment

Amount

PPIS

Interest

Certificate

Accretion

Interest

Loss/Exp

Interest

Penalties

Proceeds (1)

Interest

Shortfalls

Certificate

Rate

Pass
Thru

Method Days

Outstanding

Remaining

Statement Date:

Distributable

Current Period

(Shortfall)/

Recovery

Int Accrual

on Prior

Shortfall (3)

0.00

1-A1

109,265.68

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

1-A2

7,971.25

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

1-A3

300,712.26

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

1-A4

83,483.75

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

13,138.48

0.00

1-A5

13,138.48

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

2-A1

299,415.75

0.00

3.90%

3.99%

30/360

5.500000000%

0.00

3-A1

408,927.97

0.00

3.90%

3.99%

30/360

5.750000000%

0.00

4-A1

576,090.07

0.00

3.90%

3.99%

30/360

6.000000000%

0.00

5-A1

168,002.25

0.00

3.90%

3.99%

30/360

6.250000000%

0.00

5-A2

129,463.54

0.00

3.90%

3.99%

30/360

6.250000000%

0.00

5-A3

5,256.22

0.00

3.90%

3.99%

30/360

6.250000000%

0.00

6-A1

73,127.68

0.00

3.90%

3.99%

30/360

5.000000000%

0.00

7-A1

150,392.68

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

8-A1

429,717.47

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

8-A2

25,838.75

0.00

3.90%

3.99%

30/360

5.250000000%

0.00

8-A3

262,634.11

0.00

3.90%

3.99%

30/360

5.000000000%

0.00

8-A4

122,043.17

0.00

3.90%

3.99%

30/360

2.580000000%

0.00

8-A5

232,733.48

0.00

30/360

4.920000000%

0.00

8-A6

46,306.67

0.00

3.90%

3.99%

30/360

5.750000000%

0.00

8-A7

139,169.17

0.00

3.90%

3.99%

30/360

5.750000000%

0.00

3.90%

3.99%

30/360

0.000000000%

0.00

AX(1,8)

25,387.05

0.00

30/360

5.500000000%

0.00

AX(2-7)

14,641.55

0.00

30/360

5.500000000%

0.00

PAX(1,8)

10,786.21

0.00

30/360

5.500000000%

0.00

PAX(2-7)

7,150.05

0.00

30/360

5.500000000%

0.00

86,902.81

0.00

1.60%

1.64%

30/360

5.687343151%

0.00

22,670.92

0.00

1.00%

1.02%

30/360

5.687343151%

0.00

13,223.52

0.00

0.65%

0.67%

30/360

5.687343151%

0.00

(2) Accrued - Deductions + Additions Interest

(3) Includes interest accrued on outstanding Interest Shortfalls and/or Loss Allocations. Where applicable.

Page 15 of 38

(1) Other Interest Proceeds are additional interest amounts specifically allocated to the bond(s) and used in determining the bonds Distributable Interest.

(4) Determined as follows: (A) the ending balance of all the classes less (B) the sum of (i) the ending balance of the class and (ii) the ending balance of all classes which are not subordinate to the class divided by (A).

Structured Asset Securities Corporation

Class

Accrued

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1
Bond Interest Reconciliation

Deductions

Allocable

Deferred &

Prior

Prepay-

Other

Additions

Interest

Credit Support

Original

Current(4)

Accrual

Int. Short-

falls Due

ment

Interest

Interest (2)

Payment

Amount

PPIS

Interest

Certificate

Accretion

Interest

Loss/Exp

Interest

Penalties

Proceeds (1)

Interest

Shortfalls

Certificate

Rate

Pass
Thru

Method Days

Outstanding

Remaining

Statement Date:

Distributable

Current Period

(Shortfall)/

Recovery

Int Accrual

on Prior

Shortfall (3)

0.00

11,333.09

0.00

0.35%

0.36%

30/360

5.687343151%

0.00

7,556.97

0.00

0.15%

30/360

5.687343151%

0.00

5,696.29

0.00

0.00%

30/360

5.687343151%

0.00

7,555.80

0.00

7,555.80

0.00

0.000000000%

0.00

0.000000000%

0.00

13,138.48

0.00

7,555.80

0.00

3,789,038.86

3,783,456.18

0.00

(2) Accrued - Deductions + Additions Interest

(3) Includes interest accrued on outstanding Interest Shortfalls and/or Loss Allocations. Where applicable.

Page 16 of 38

(1) Other Interest Proceeds are additional interest amounts specifically allocated to the bond(s) and used in determining the bonds Distributable Interest.

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Statement Date:

Other Related Information

Special Hazard Coverage

Beginning

Balance

Current

Reduction

Ending

Balance

Beginning

Balance

Current

Reduction

Beginning

Balance

Current

Reduction

Ending

Balance

Fraud Loss Coverage

Bankruptcy Loss Coverage

Ending

Balance

Number of Payoffs:
Aggregate Payoff Amounts:

Number of Curtailments:
Aggregate Curtailment Amounts:

Number of Loans in Foreclosure:
Book Value of Loans in Foreclosure:

Prior Realized Losses Allocated to the Certificates:
Current Realized Losses Allocated to the Certificates:
Cumulative Realized Losses Allocated to the Certificates since Cutoff:

Total

7,975,030.00

0.00

7,975,030.00

0.00

100,000.00

0.00

9,483,939.49

673

0.00

1,063,162.06

0.00

Page 17 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

ABN AMRO Acct: 722144.1

1.19%

1.23%

0.00%

27-Dec-04

9,615,598

0.08%

0.11%

0.00%

26-Nov-04

875,597

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 18 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 1

ABN AMRO Acct: 722144.1

0.46%

1.41%

0.00%

27-Dec-04

1,736,406

0.00%

26-Nov-04

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 19 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 2

ABN AMRO Acct: 722144.1

1.95%

1.92%

0.00%

27-Dec-04

1,293,658

0.00%

26-Nov-04

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 20 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 3

ABN AMRO Acct: 722144.1

1.51%

1.43%

0.00%

27-Dec-04

1,257,307

0.00%

26-Nov-04

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 21 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 4

ABN AMRO Acct: 722144.1

1.22%

1.26%

0.00%

27-Dec-04

1,479,697

0.00%

26-Nov-04

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 22 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 5

ABN AMRO Acct: 722144.1

1.30%

1.48%

0.00%

27-Dec-04

851,070

0.00%

26-Nov-04

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 23 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 6

ABN AMRO Acct: 722144.1

0.00%

27-Dec-04

0.00%

26-Nov-04

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 24 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 7

ABN AMRO Acct: 722144.1

0.00%

27-Dec-04

0.00%

26-Nov-04

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 25 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Asset-Backed Facts ~ 15 Month Historical Loan Status Summary

Distribution

Date

Delinq 1 Month

Delinq 2 Months

Delinq 3+ Months

Foreclosure

REO

Modifications

Specially Serviced

Bankruptcy

# Balance

Delinquency Aging Categories

Special Event Categories (1)

Statement Date:

Pool Group 8

ABN AMRO Acct: 722144.1

1.28%

1.10%

0.00%

27-Dec-04

2,997,461

0.42%

0.32%

0.00%

26-Nov-04

875,597

(1) Note: Modification, Specially Serviced & Bankruptcy Totals are Included in the Appropriate Delinquency Aging Category

Page 26 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

2,530

97.99%

779,217,936

97.71%

1.25%

1.20%

0.00%

354

6.01%

5.76%

7,556

9,483,939

26-Nov-04

2,562

99.23%

790,017,398

99.06%

0.77%

0.87%

0.00%

355

6.01%

5.76%

7,600

6,902,791

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 27 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 1

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

217

8.40%

122,767,283

15.39%

0.00%

348

349

5.56%

5.31%

26-Nov-04

217

8.40%

122,883,907

15.41%

0.00%

349

350

5.56%

5.31%

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 28 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 2

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

307

11.89%

67,415,448

8.45%

0.97%

0.84%

0.00%

355

5.83%

5.58%

570,781

26-Nov-04

310

12.01%

68,012,426

8.53%

0.96%

1.05%

0.00%

355

356

5.83%

5.58%

722,309

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 29 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 3

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

398

15.41%

87,857,573

11.02%

1.00%

0.97%

0.00%

356

6.07%

5.82%

7,556

859,568

26-Nov-04

402

15.57%

88,823,180

11.14%

0.50%

0.48%

0.00%

357

6.07%

5.82%

424,699

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 30 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 4

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

573

22.19%

117,540,563

14.74%

1.38%

1.59%

0.00%

356

6.31%

6.06%

1,903,197

26-Nov-04

581

22.50%

119,959,016

15.04%

0.85%

1.25%

0.00%

357

6.31%

6.06%

7,600

1,514,593

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 31 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 5

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

308

11.93%

57,416,273

7.20%

3.75%

5.05%

0.00%

356

6.56%

6.31%

3,054,419

26-Nov-04

320

12.39%

60,494,900

7.59%

0.62%

0.48%

0.00%

356

357

6.56%

6.31%

292,982

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 32 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 6

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

3.37%

18,622,758

2.34%

0.00%

353

5.20%

4.95%

26-Nov-04

3.37%

18,629,239

2.34%

1.14%

0.73%

0.00%

354

5.20%

4.95%

137,000

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 33 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 7

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

173

6.70%

35,582,899

4.46%

0.57%

0.52%

0.00%

353

5.56%

5.31%

186,939

26-Nov-04

174

6.74%

35,780,236

4.49%

0.57%

0.56%

0.00%

354

5.56%

5.31%

202,292

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 34 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Asset-Backed Facts ~ 15 Month Historical Payoff/Loss Summary

Distribution

Date

Ending Pool (1)

Payoffs(2)

Penalties

Appraisal Reduct. (2)

Liquidations (2)

Realized Losses (2)

Remaining Term

Curr Weighted Avg.

# Balance

# Amount

# Balance

# Amount

Life

Coupon Remit

Statement Date:

Pool Group 8

Amort

ABN AMRO Acct: 722144.1

Series 2004-20

27-Dec-04

467

18.09%

272,015,139

34.11%

0.85%

1.06%

0.00%

355

6.08%

5.83%

2,909,037

26-Nov-04

471

18.24%

275,434,493

34.54%

1.26%

1.29%

0.00%

356

6.08%

5.83%

3,608,915

(1) Percentage based on pool as of cutoff. (2) Percentage based on pool as of beginning of period.

Page 35 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Modified Loan Detail

Disclosure

Control #

Modification

Date

Cutoff

Maturity

Date

Modification

Description

Modified

Maturity

Date

Statement Date:

Page 36 of 38

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

ABN AMRO Acct: 722144.1

Realized Loss Detail

Period

Disclosure

Control #

Appraisal

Date

Appraisal

Value

Beginning
Scheduled

Balance

Gross

Proceeds

Gross Proceeds

as a % of

Sched. Balance

Aggregate

Liquidation
Expenses *

Net

Liquidation

Proceeds

Net Proceeds

as a % of

Sched. Balance

Realized

Loss

Statement Date:

Current Total
Cumulative

Page 37 of 38

* Aggregate liquidation expenses also include outstanding P&I advances and unpaid servicing fees, unpaid trustee fees, etc..

Structured Asset Securities Corporation

Payment Date:
Prior Payment:
Next Payment:
Record Date:

27-Dec-04
27-Dec-04

26-Nov-04

25-Jan-05

30-Nov-04

Mortgage Pass-Through Certificates

Series 2004-20

Historical Collateral Level REO Report

Property

Type

Statement Date:

State

Actual

Balance

Scheduled

Balance

Recent

Appraisal

Value

Appraisal

Reduction

Amount

Date

Liquidated

Liquidation

Proceeds

Liquidation

Expenses

Realized

Loss

Disclosure

Control #

REO

Date

City

Appraisal

Date

ABN AMRO Acct: 722144.1

Page 38 of 38

Structured Asset Securities Corp Mortgage Pass-Through Certificates, Series 2004-20 8-K