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) August 25, 2004

Structured Asset Securities Corporation
(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 2004-13, which was made on August 25, 2004.

Section 9 - Financial Statements and Exhibits

Item 9.01 Financial Statements and Exhibits.

99.1 Monthly distribution report pursuant to section 5.02 of the Trust Agreement for the distribution on August 25, 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: August 30, 2004

STRUCTURED ASSET SECURITIES CORPORATION

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

Reporting Package Table of Contents

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Administrator:
Rita Lopez 312.904.0351
rita.lopez@abnamro.com

Analyst:
David Ratner 714.259.6251
david.ratner@abnamro.com

Statement Date:

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

Statements to Certificateholders
Bond Interest Reconciliation
Substitution Detail History
Other Related Information

Cash Reconciliation Summary

Shortfall Summary Report
Asset-Backed Facts ~ 15 Month Loan Status Summary

Realized Loss Detail
Historical REO Report

Page 2-3
Page 4
Page 5
Page 6

Page 7-9

Page 10
Page 11-13

Page 14
Page 15

Page(s)

Information is available for this issue from the following sources

Issue Id:

Monthly Data File
Name:

SASC0413

SASC0413_200408_3.ZIP

Closing Date:

First Payment Date:

Rated Final Payment: Date:

30-Jun-04
26-Jul-04

27-Jul-37

Parties to The Transaction

Issuer: Structured Asset Securities Corporation

Underwriter: Lehman Brothers Inc.

Master Servicer: Aurora Loan Services, Inc.

Rating Agency: Standard & Poor's/Moody's Investors Service, Inc./Fitch Ratings

800.246.5761

LaSalle Factor Line

LaSalle Web Site

Servicer Web Site

www.alservices.com

www.etrustee.net

Page 1 of 15

Class

CUSIP

Original

Opening

Principal

Negative

Closing

Interest

Pass-Through

Per $ 1000

Next Rate(3)

WAC:
WAMM:

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

6.021178%

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

STRUCTURED ASSET SECURITIES CORPORATION

Mortgage Pass-Through Certificates

Series 2004-13

Face Value (1)

Balance

Payment

Adj. or Loss

Amortization

Balance

Payment (2)

Adjustment

Rate

356

REMIC II

Statement Date:

ABN AMRO Acct: 721911.2

1000.000000000

0.000000000

1000.000000000

4.583333986

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BVL2

1-A1

5,111,000.00

0.00

5,111,000.00

23,425.42

999.167474280

0.894860697

0.000000000

998.272613582

4.579517635

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BVM0

1-A2

39,949,000.00

39,915,741.43

35,748.79

0.00

39,879,992.64

182,947.15

1000.000000000

0.000000000

1000.000000000

4.583335156

Fixed

0.00

0.000000000

5.50000000%

0.000000000

86359BVN8

1-A3

1,829,000.00

0.00

1,829,000.00

8,382.92

990.804901654

11.570844330

0.000000000

979.234057323

4.790563946

5.798676714%

0.00

0.000000000

5.80202693%

0.000000000

86359BVT5

2-A1

415,572,000.00

411,750,774.59

4,808,518.92

0.00

406,942,255.67

1,990,824.24

999.050355400

0.950661081

0.000000000

998.099694319

4.804917595

5.768359688%

0.00

0.000000000

5.77138211%

0.000000000

86359BVP3

10,861,000.00

10,850,685.91

10,325.13

0.00

10,840,360.78

52,186.21

999.050356354

0.950660221

0.000000000

998.099696133

4.804917127

5.768359688%

0.00

0.000000000

5.77138211%

0.000000000

86359BVQ1

3,620,000.00

3,616,562.29

3,441.39

0.00

3,613,120.90

17,393.80

999.050357513

0.950663212

0.000000000

998.099694301

4.804917098

5.768359688%

0.00

0.000000000

5.77138211%

0.000000000

86359BVR9

1,930,000.00

1,928,167.19

1,834.78

0.00

1,926,332.41

9,273.49

999.050355240

0.950663114

0.000000000

998.099692126

4.804920071

5.768359688%

0.00

0.000000000

5.77138211%

0.000000000

86359BVU2/U85985RQ1

1,689,000.00

1,687,396.05

1,605.67

0.00

1,685,790.38

8,115.51

999.050352210

0.950662983

0.000000000

998.099689227

4.804917127

5.768359688%

0.00

0.000000000

5.77138211%

0.000000000

86359BVV0/U85985RR9

1,448,000.00

1,446,624.91

1,376.56

0.00

1,445,248.35

6,957.52

999.050358389

0.950657344

0.000000000

998.099701045

4.804924383

5.768359688%

0.00

0.000000000

5.77138211%

0.000000000

86359BVW8/U85985RS7

728,538.00

727,846.15

692.59

0.00

727,153.56

3,500.57

0.000000000

Fixed

0.00

0.000000000

N/A

0.000000000

86359BVS7

100.00

0.00

0.000000000

0.00

0.000000000

N/A

0.000000000

9ABSR034

R-1

0.00

Total P&I Payment

0.00

482,737,638.00

478,863,798.52

7,166,550.66

Total

474,000,254.69

4,863,543.83

0.00

2,303,006.83

Page 2 of 15

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 $ 0

Next Rate(3)

WAC:
WAMM:

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

6.021178%

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

STRUCTURED ASSET SECURITIES CORPORATION

Mortgage Pass-Through Certificates

Series 2004-13

Face Value (1)

Balance

Payment

Adj. or Loss

Amortization

Balance

Payment (2)

Adjustment

Rate

356

Grantor Trust

Statement Date:

ABN AMRO Acct: 721911.2

0.000000000

0.00

10,713.04

0.000000000

N/A

0.000000000

9ABSR032

0.00

10,713.04

0.000000000

0.00

0.000000000

N/A

0.000000000

9ABSR033

0.00

Total P&I Payment

0.00

10,713.04

0.00

10,713.04

Total

0.00

10,713.04

Page 3 of 15

STRUCTURED ASSET SECURITIES CORPORATION

Class

Accrued

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

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

23,425.42

0.00

4.20%

4.27%

30/360

5.500000000%

0.00

1-A2

182,947.15

0.00

4.20%

4.27%

30/360

5.500000000%

0.00

1-A3

8,382.92

0.00

4.20%

4.27%

30/360

5.500000000%

0.00

2-A1

1,990,824.24

0.00

4.20%

4.27%

30/360

5.802026934%

0.00

52,186.21

0.00

1.95%

1.98%

30/360

5.771382108%

0.00

17,393.80

0.00

1.20%

1.22%

30/360

5.771382108%

0.00

9,273.49

0.00

0.80%

0.81%

30/360

5.771382108%

0.00

8,115.51

0.00

0.45%

0.46%

30/360

5.771382108%

0.00

6,957.52

0.00

0.15%

30/360

5.771382108%

0.00

3,500.57

0.00

0.00%

30/360

5.771382108%

0.00

10,713.04

0.00

10,713.04

0.00

30/360

0.000000000%

0.00

30/360

0.000000000%

0.00

10,713.04

0.00

2,303,006.83

2,313,719.87

0.00

(2) Accrued - Deductions + Additions Interest

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

Page 4 of 15

(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

Substitution Detail History

ABN AMRO Acct: 721911.2

Series 2004-13

Mortgage Pass-Through Certificates

30-Jul-04

27-Sep-04

26-Jul-04

25-Aug-04

Record Date:

Next Payment:

Prior Payment:

Payment Date:

Statement Date:

Property ID

Deleted Loan

Qualified Substitute

Scheduled Prin Bal

Page 5 of 15

Original Property

Per Section 7.01(a)(i) of the Property Management and Lease Servicing Agreement, aggregate Appraised Value of the Qualified Substitute Mortgaged Properties acquired by the
Issuer since the Closing Date in connection with the substitution or exchange pursuant to Section 7.01 is not to exceed 25% of the aggregate Initial Appraised Value of the
Mortgaged Properties.

(A)

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

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

4,827,376.00

0.00

9,654,753.00

0.00

100,000.00

0.00

4,061,782.79

459

0.00

0.00
0.00

0.00

346,235.28

Page 6 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

Statement Date:

Cash Reconciliation Summary

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

740,011.02

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

2,333,657.28

Unscheduled Interest:
Prepayment Penalties

10,713.04

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

10,713.04

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

2,313,719.86

0.00
0.00
0.00
0.00

0.00

139,484.06
316,041.70
455,525.76

346,235.28

4,061,782.79

0.00
0.00
0.00

4,408,018.07
4,863,543.83

7,177,263.69

478,863,799.22

2,417

455,525.76

4,408,018.07

0.00
0.00

0.00

474,000,255.39

2,392

312,834.97

1,591,684.89

316,041.70

1,593,646.26

319,293.11

1,614,314.78

30,650.46

0.00
0.00

69,112.83

99,763.29

0.00
0.00
0.00
0.00
0.00
0.00

0.00

Advance Summary (Advance Made by Servicer)

)

(30,650.46

2,313,719.86

Interest Not Advanced (

Current Period

)

0.00

1,593,646.26

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(1,571,016.37

)

(309,583.56

0.00

Page 7 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

Statement Date:

Cash Reconciliation Summary Pool 1

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

47,377.78

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

226,235.89

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

224,175.99

0.00
0.00
0.00
0.00

0.00

5,332.08

21,656.49
26,988.57

9,894.36

0.00
0.00
0.00
0.00

9,894.36

36,882.93

261,058.92

48,911,124.05

26,988.57

9,894.36

0.00
0.00

0.00

48,874,241.12

21,010.83

172,085.38

21,656.49

178,858.11

21,656.49

183,418.53

2,059.90

0.00
0.00

8,129.91

10,189.82

0.00
0.00
0.00
0.00
0.00
0.00

0.00

Advance Summary (Advance Made by Servicer)

)

(2,059.90

224,175.99

Interest Not Advanced (

Current Period

)

0.00

178,858.11

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(167,524.97

)

(21,010.83

0.00

Page 8 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

Statement Date:

Cash Reconciliation Summary Pool 2

Current Scheduled Interest

Interest Summary

Less Deferred Interest

Plus Gross Advance Interest

Less PPIS Reducing Scheduled Int

692,633.24

0.00
0.00

Less ASER Interest Adv Reduction

0.00

Less Other Adjustment

0.00

Total

2,107,421.39

Unscheduled Interest:
Prepayment Penalties

10,713.04

Yield Maintenance Penalties

0.00

Other Interest Proceeds

0.00

Total

10,713.04

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

2,089,543.87

0.00
0.00
0.00
0.00

0.00

134,151.98
294,385.21
428,537.19

336,340.92

4,061,782.79

0.00
0.00
0.00

4,398,123.71
4,826,660.90

6,916,204.77

429,952,675.17

2,332

428,537.19

4,398,123.71

0.00
0.00

0.00

425,126,014.27

2,307

291,824.14

1,419,599.51

294,385.21

1,414,788.15

297,636.62

1,430,896.25

28,590.56

0.00
0.00

60,982.92

89,573.47

0.00
0.00
0.00
0.00
0.00
0.00

0.00

Advance Summary (Advance Made by Servicer)

)

(28,590.56

2,089,543.87

Interest Not Advanced (

Current Period

)

0.00

1,414,788.15

Workout Fees
Liquidation Fees

0.00
0.00

Less Non Recovered

)

(1,403,491.40

)

(288,572.73

0.00

Page 9 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

Interest Adjustments Summary

Statement Date:

0.00

Special Servicing Fees

Workout Fees

Liquidation Fees

Legal Fees

0.00

Misc. Fees & Expenses Paid by/to Servicer

Interest Paid to Servicer on Outstanding Advances

0.00

ASER Interest Advance Reduction

Interest Not Advanced (Current Period)

Recoup of Prior Advances by Servicer

0.00

Servicing Fees Paid Servicer on Loans Not Advanced

Misc. Fees & Expenses Paid by Trust

0.00

Shortfall Due to Rate Modification

Total Shortfall Allocated to the Bonds

Total Interest Adjustment to the Bonds

0.00

Shortfall Allocated to the Bonds:

Excess Allocated to the Bonds:

Other Interest Proceeds Due the Bonds

Yield Maintenance Penalties Due the Bonds

Prepayment Penalties Due the Bonds

Recovered ASER Interest Due the Bonds

Recovered Interest Due the Bonds

Less Total Shortfall Allocated to the Bonds

Total Excess Allocated to the Bonds

10,713.04

10,713.04

Total Excess Allocated to the Bonds

10,713.04

0.00

Aggregate Interest Adjustment Allocated to the Bonds

0.00

10,713.04

0.00

Prepayment Interest Excess Due the Bonds

0.00

ARD Excess Interest

0.00

Other Interest Loss

0.00

Net Prepayment Int. Shortfalls Allocated to the Bonds

Page 10 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

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: 721911.2

0.96%

0.94%

0.00%

25-Aug-04

4,452,876

0.00%

26-Jul-04

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

Page 11 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

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 1

ABN AMRO Acct: 721911.2

1.18%

2.04%

0.00%

25-Aug-04

995,000

0.00%

26-Jul-04

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

Page 12 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

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 2

ABN AMRO Acct: 721911.2

0.95%

0.81%

0.00%

25-Aug-04

3,457,876

0.00%

26-Jul-04

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

Page 13 of 15

STRUCTURED ASSET SECURITIES CORPORATION

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

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

ABN AMRO Acct: 721911.2

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 14 of 15

* 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:

25-Aug-04
25-Aug-04

26-Jul-04

27-Sep-04

30-Jul-04

Mortgage Pass-Through Certificates

Series 2004-13

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: 721911.2

Page 15 of 15

Structured Asset Securities CORP Mortgage Pass-Through Certificates, Series 2004-13 8-K