UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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)

~~September 22~~October 21, 2025

AMKOR TECHNOLOGY, INC.

(Exact name of registrant as specified in its charter)

Delaware

000-29472

23-1722724

(State or Other Jurisdiction of Incorporation)

(Commission File Number)

(IRS Employer Identification No.)

2045 EAST INNOVATION CIRCLE

TEMPE, AZ 85284

(Address of principal executive offices, including zip code)

(480) 821-5000

(Registrant’s telephone number, including area code)

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:

☐ 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))

Securities registered pursuant to Section 12(b) of the Act:


Title of Each Class	Trading Symbol	Name of Each Exchange on Which Registered
Common Stock, $0.001 par value	AMKR	The NASDAQ Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐o

Item 1 2.0102. ~~Entry~~Results ~~into~~of aOperations ~~Material~~and ~~Definitive~~Financial ~~Agreement~~Condition.

On ~~September 22~~October 27, 2025, Amkor Technology, Inc., announced in a ~~Delaware~~press ~~corporation~~release (its financial performance for the ~~“Company”)~~three ~~issued~~and ~~$500~~nine months ended September 30,~~000,000~~ ~~aggregate~~2025. ~~principal~~The ~~amount~~information ofin ~~its~~this 5Item 2.~~875%~~02 ~~Senior~~in ~~Notes~~this ~~due~~Current ~~2033~~Report ~~(the~~on ~~“2033~~Form ~~Notes~~8-K and Exhibit 99.1 attached hereto is being furnished and shall not be deemed “filed”), ~~pursuant~~for topurposes anof ~~Indenture~~Section 18 of the Securities Exchange Act of 1934, as amended (the “~~Indenture~~Exchange Act”), ~~between~~or ~~the~~otherwise ~~Company~~subject ~~and~~to ~~U.S.~~liability ~~Bank~~under ~~Trust~~that ~~Company~~section, ~~National~~nor ~~Association~~shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as ~~trustee,~~amended ~~relating~~(the to"Securities Act"), or the ~~issuance~~Exchange Act, regardless of ~~the~~any ~~2033~~general ~~Notes~~incorporation language in such filing.

UItem 5.S.02 ~~Bank~~Departure ~~Trust~~of ~~Company,~~Directors ~~National~~or ~~Association,~~Principal ~~the~~Officers; ~~trustee~~Election ~~under~~of ~~the~~Directors; ~~Indenture,~~Appointment ~~also~~of ~~serves~~Principal ~~as trustee under the indenture governing the Company’s 6~~Officers.~~625% Senior Notes due 2027 (the “2027 Notes”).~~

~~The~~On ~~terms~~October 21, 2025, Mr. Giel Rutten, the President and ~~conditions~~Chief Executive Officer of Amkor Technology, Inc. (the ~~Indenture~~“Company”), provided notice that he would voluntarily retire as President and Chief Executive Officer on December 31, 2025. Mr. Rutten will continue serving as a member of the ~~2033~~Board ~~Notes~~of ~~described~~Directors of the Company (the “Board”). Following its Chief Executive Officer succession planning process, the Board has unanimously appointed Mr. Kevin Engel to succeed Mr. Rutten as President and Chief Executive Officer and as a member of the Board, with each appointment effective immediately after Mr. Rutten’s retirement as President and Chief Executive Officer. Mr. Engel joined the Company in ~~Item~~August 22004 and currently serves as Executive Vice President, Chief Operating Officer of the Company, which role will cease when his appointment as President and Chief Executive Officer of the Company becomes effective.03 ~~hereof~~To ~~are~~assist ~~incorporated~~in bythe ~~reference~~leadership ~~into~~transition, ~~this~~Mr. ~~Item~~Rutten 1has agreed that, upon the effectiveness of Mr.01 Engel’s appointment, Mr. Rutten will provide strategic and advisory services to the Company through March 31, 2026.

~~Item 2~~Mr.~~03.~~ ~~Creation~~Engel ofwill aserve ~~Direct~~as ~~Financial~~a ~~Obligation~~director orof anthe ~~Obligation~~Board ~~under~~until anthe ~~Off-Balance~~Company’s ~~Sheet~~annual ~~Arrangement~~meeting of astockholders ~~Registrant~~to be held in 2026 and until his successor has been elected and qualified or until his earlier resignation or removal.

~~The~~Over ~~information~~his ~~set~~20 ~~forth~~years inwith ~~Item~~the 1Company, Mr.01 ~~hereof~~Engel ishas ~~incorporated~~held byexecutive ~~reference~~leadership ~~into~~roles ~~this~~of ~~Item~~increasing 2responsibility including serving as Executive Vice President, Business Units from 2023 to 2025 and Corporate Vice President, Flip Chip/Wafer Level Business Unit from 2020 to 2023.03 Mr. Engel has nearly 30 years of experience in the electronics and semiconductor industry, including over 20 years of service with the Company.

OnIn ~~September~~connection ~~22,~~with ~~2025~~Mr. Engel’s appointment, Mr. Engel and the Company entered into an Employment Letter Agreement (the ~~Indenture~~“Employment ~~relating~~Agreement”). Pursuant to the ~~issuance~~Employment byAgreement, Mr. Engel will serve as the President and Chief Executive Officer of the Company and, subject to the approval of the Board and election by the stockholders (if applicable), as a member of the Board, in each case effective immediately after Mr. Rutten’s retirement. The Employment Agreement has no specified term, and Mr. Engel’s employment with the Company will be on an at-will basis. Under the Employment Agreement, Mr. Engel’s starting annual base salary will be $~~500~~900,000,~~000~~ ~~aggregate~~subject ~~principal~~to ~~amount~~review by the Compensation Committee of the ~~2033~~Board. ~~Notes~~Mr. Engel will be eligible for a cash bonus under the Company’s annual incentive plan with the target annual incentive amount of 125% of his base salary. The ~~material~~actual amount payable to Mr. Engel as an annual cash bonus will be dependent upon the achievement of performance targets which are established by the Compensation Committee of the Board and may range from 0 to 200% of the stated target bonus. In connection with Mr. Engel’s appointment as President and Chief Executive Officer, in February 2026, Mr. Engel will be awarded (i) long term incentive equity awards with a total grant date target value of $5.0 million, subject to substantially the same split between performance-based restricted stock units and time-based restricted stock units and terms and conditions (including vesting and performance conditions) as established for other executive officers of the ~~Indenture~~Company and (ii) long term incentive equity awards with a total grant value of $1.0 million in the ~~2033~~form ~~Notes~~of ~~are~~restricted asstock ~~follows:~~units, vesting in two equal installments in December 2026 and December 2027.

~~Maturity~~Also in connection with Mr. ~~The~~Engel’s ~~2033~~appointment, ~~Notes~~Mr. ~~mature~~Engel onand ~~October~~the 1Company entered into an executive severance agreement (the “Severance Agreement”). Pursuant to the Severance Agreement, ~~2033~~upon termination of Mr. Engel’s employment by the Company without “Cause” or by Mr. Engel for “Good Reason,” ~~subject~~each as defined in the Severance Agreement, Mr. Engel will be entitled to: ~~earlier~~(i) ~~redemption~~where such termination occurs within three months prior, or ~~repurchase~~twenty-four months after, a Change in Control, (A) a lump sum equal to two times Mr. Engel’s then-current base salary and target bonus, (B) a pro-rata target bonus for the year of termination, (C) a lump sum payment of health insurance premiums for eighteen months, (D) full-vesting acceleration for time-vesting equity awards, and (E) payment of salary, unused vacation time, and vested benefits earned prior to termination; or (ii) in all other cases, (A) continuation of Mr. Engel’s then-current base salary and target bonus for an eighteen-month period (or 1.5 times the sum of his annual base salary and target bonus), (B) a pro-rata bonus for the year of termination determined based on the actual bonus, if any, he would have been paid for such year absent such termination, (C) bi-weekly installment payments of health insurance premiums for eighteen months, (D) vesting acceleration of the portion of all unvested time-vesting equity awards that would have

~~Interest.~~vested ~~The~~within ~~2033~~eighteen ~~Notes~~months ~~accrue~~after ~~interest~~a attermination, aand ~~rate~~(E) payment of ~~5.875%~~salary, ~~per~~unused ~~year~~vacation time, and vested benefits earned prior to termination. ~~Interest~~Mr. onEngel’s ~~the~~right ~~2033~~to ~~Notes~~receive severance benefits is ~~paid~~contingent ~~semi-annually~~upon him executing and not revoking a general release of claims in ~~arrears~~favor onof ~~April~~the 1Company and ~~October~~its 1,affiliates ~~beginning~~and onhis ~~April~~compliance 1with certain non-competition, ~~2026~~non-solicitation, non-disparagement, confidentiality, and intellectual property assignment obligations.

~~Ranking~~There is no arrangement or understanding between Mr. ~~The~~Engel ~~2033~~and ~~Notes~~any ~~are~~other ~~the~~person ~~senior~~pursuant ~~unsecured~~to ~~obligations~~which Mr. Engel is to be selected as an officer of the Company that would require disclosure under Item 401(b) of Regulation S-K. Additionally, there is no family relationship between Mr. Engel and any other person that would require disclosure under Item 401(d) of Regulation S-K.

~~Guarantees~~In connection with the announced transition, Mr. ~~Guardian~~Rutten ~~Assets~~has entered into a letter agreement (the “Retirement Agreement”) amending his existing employment agreement to reflect his impending retirement. Under the Retirement Agreement, ~~Inc~~Mr. ~~initially~~Rutten ~~guarantees~~will provide strategic and transition advisory services to the ~~2033~~Company ~~Notes~~until March 31, 2026, his current salary and ~~each~~benefits will continue through March 31, 2026, his outstanding equity awards will continue vesting in accordance with their terms so long as he remains a service provider to the Company, and he will be fully eligible for the 2025 annual executive incentive bonus plan payment (to be paid in 2026), subject to the achievement of applicable performance metrics and continued employment through the payment date. In accordance with the Company’s ~~direct~~existing policies, the Company will continue housing payments for Mr. Rutten in Singapore through March 31, 2026, and, ~~indirect~~following ~~wholly-owned~~the ~~domestic~~cessation ~~subsidiaries~~of ~~that~~his ~~guarantees~~service as a strategic advisor, the Company will either continue to provide for Mr. Rutten’s Uparticipation in Amkor Singapore’s medical benefit plan, subject to continued eligibility and the terms of such plan, or reimburse him for the cost of equivalent coverage through December 2026.S Beginning April 1, 2026, Mr. ~~senior~~Rutten ~~secured~~will ~~credit~~become ~~facility~~a non-employee director eligible to receive non-employee director compensation and will continue to be ~~required~~covered by the Company’s tax equalization program with respect to ~~guarantee~~all years when he was an employee of the ~~2033~~Company ~~Notes~~or any of the Company’s direct and indirect subsidiaries. No other payments or compensation are due by the Company to Mr. Rutten.

~~Optional Redemption.~~ The ~~Company~~foregoing ~~may~~descriptions ~~redeem~~are ~~some~~qualified orby ~~all~~reference ~~of the 2033 Notes at any time prior~~ to ~~October 1, 2028, at a price equal to~~ the ~~sum~~terms of ~~(a) 100% of~~ the ~~principal~~Employment ~~amount~~Agreement, ofSeverance ~~the 2033 Notes being redeemed~~Agreement, ~~(b) accrued~~ and ~~unpaid interest to, but excluding,~~ the ~~redemption~~Retirement ~~date~~Agreement, ~~and~~which ~~(c)~~are afiled ~~“make-whole”~~herewith ~~premium.~~as ~~The~~Exhibits ~~Company may redeem some or all of the 2033 Notes on or after October~~ 10.1, ~~2028 at descending prices, starting at 102~~10.~~938%~~2 ~~of the principal amount of the 2033 Notes being redeemed, plus accrued~~ and ~~unpaid interest to, but excluding, the redemption date~~10. ~~In addition~~3, ~~at any time prior to October 1~~respectively, ~~2028, the Company may redeem up to 40% of the 2033 Notes with the proceeds of certain equity offerings at 105.875% of the principal amount of the 2033 Notes plus accrued~~ and ~~unpaid~~are ~~interest~~incorporated ~~to,~~herein ~~but~~by ~~excluding, the redemption date~~reference.

~~Change~~Item ~~of Control~~7.01 ~~Upon~~Regulation aFD change in control (as defined in the Indenture), the Company will be required to make an offer to repurchase the 2033 Notes at a price equal to 101% of the principal amount of 2033 Notes outstanding plus accrued and unpaid interest to, but excluding, the date of repurchaseDisclosure.

~~Covenants.~~On ~~The~~October ~~Indenture~~27, ~~contains~~2025, ~~covenants~~the ~~limiting~~Company issued a press release announcing, among other ~~things~~announcements, ~~the~~Mr. ~~Company~~Rutten’s ~~ability~~retirement as President and Chief Executive Officer and the ~~ability~~appointment of Mr. Engel as President and Chief Executive Officer and Director of the Company’s. ~~subsidiaries~~A ~~to:~~copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference.

~~•incur~~The ~~debt~~information atin ~~subsidiaries~~this ~~that~~Item do7.01 in this Current Report on Form 8-K and Exhibit 99.1 attached hereto shall not ~~guarantee~~be deemed to be “filed” for purposes of Section 18 of the ~~2033~~Exchange ~~Notes;~~Act, or otherwise subject to the liabilities of that section, nor shall it be deemed to be incorporated by reference in any filing under the Securities Act or the Exchange Act, except as expressly set forth by specific reference in such filing.

•incur liens;

•engage in sale and leaseback transactions; and

•consolidate, merge with or convey, transfer or lease all or substantially all of our or their assets to another person.

These covenants are subject to a number of important exceptions and qualifications.

Events of Default. The following constitute events of default under the Indenture that could, subject to certain conditions, cause the unpaid principal on the 2033 Notes to become due and payable:

(a) the Company’s failure to pay when due an installment of interest on the 2033 Notes that continues for thirty (30) days or more;

(b) the Company’s failure to pay when due the principal, or premium, if any, on the 2033 Notes;

(d) the Company’s or any of its subsidiaries’ failure to perform or observe any other covenant, representation, warranty or other agreements contained in the 2033 Notes or the Indenture for a period of sixty (60) days after notice of default is given;

(e) the Company’s or any of its subsidiaries’ default under any mortgage, indenture or other instrument under which there may be issued or by which there may be secured or evidenced any indebtedness for borrowed money, or the guarantee thereof, in an aggregate principal amount of at least $100,000,000, if such default is caused by a failure to pay principal at maturity thereof or results in the acceleration of such indebtedness prior to maturity;

(f) the Company or any of its significant subsidiaries, or any group of subsidiaries that, taken together, would constitute a significant subsidiary, fail to pay final judgments in excess of $100,000,000 in the aggregate, and such judgments are not paid, discharged or stayed for sixty (60) days or more; and

(g) certain events of bankruptcy or insolvency of the Company or any of its significant subsidiaries, or any group of subsidiaries that, taken together, would constitute a significant subsidiary.

The descriptions of the Indenture and the 2033 Notes do not purport to be complete and are qualified in their entirety by reference to the Indenture and the related form of note, which are attached hereto as Exhibit 4.1 and Exhibit 4.2, respectively, to this Current Report on Form 8-K and are incorporated herein by reference.

Item 8.01. Other Events.

The Company today announced that it has issued a notice for the redemption of all $400,000,000 aggregate principal amount of its outstanding 2027 Notes, with the redemption to be effective on October 9, 2025. As provided in the indenture governing the 2027 Notes, the redemption price will be 100% of the principal amount of the 2027 Notes, or $1,000 per $1,000 principal amount thereof, paid in cash. In addition, the Company will pay accrued and unpaid interest on the 2027 Notes to, but excluding, the redemption date, in accordance with the terms of the indenture. The Company plans to fund the redemption of the 2027 Notes with the proceeds from its issuance of the 2033 Notes.

On September 22, 2025, the Company issued a press release announcing the closing of its offering of the 2033 Notes and the notice of redemption of the 2027 Notes. A copy of this press release is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

Exhibit						Description
4.1						Indenture, dated September 22, 2025, by and between Amkor Technology, Inc. and U.S. Bank Trust Company, National Association, as trustee.
10.1						Retirement Agreement, dated October 21, 2025, between Amkor Technology, Inc. and Giel Rutten
4.2						Form of Note for Amkor Technology, Inc.’s 5.875% Senior Notes due 2033 (incorporated by reference to Exhibit 4.1 hereof).
10.2						Employment Letter Agreement, dated October 21, 2025, between Amkor Technology, Inc. and Kevin Engel
99.1						Press release, dated September 22, 2025, announcing closing of Amkor Technology, Inc.'s 5.875% Senior Notes due 2033 and notice of redemption of its 6.625% Senior Notes due 2027.
10.3						Executive Severance Agreement, dated October 21, 2025, between Amkor Technology, Inc. and Kevin Engel
99.1						Press Release dated October 27, 2025, which is furnished (not filed) herewith.
104						Cover Page Interactive Data File (embedded within the Inline XBRL document)

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.

AMKOR TECHNOLOGY, INC. By: /s/ ~~Mark~~Megan N.Faust ~~Rogers~~Megan ~~Mark~~Faust ~~N. Rogers~~ Executive Vice President, ~~General~~Chief ~~Counsel,~~Financial Officer and ~~Corporate Secretary~~Treasurer

Date: ~~September 22~~ October 27, 2025

Filing Compare · AMKOR TECHNOLOGY, INC.