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, 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. ☐

Item 1.01. Entry into a Material Definitive Agreement.

On September 22, 2025, Amkor Technology, Inc., a Delaware corporation (the “Company”) issued $500,000,000 aggregate principal amount of its 5.875% Senior Notes due 2033 (the “2033 Notes”), pursuant to an Indenture (the “Indenture”) between the Company and U.S. Bank Trust Company, National Association, as trustee, relating to the issuance of the 2033 Notes.

U.S. Bank Trust Company, National Association, the trustee under the Indenture, also serves as trustee under the indenture governing the Company’s 6.625% Senior Notes due 2027 (the “2027 Notes”).

The terms and conditions of the Indenture and the 2033 Notes described in Item 2.03 hereof are incorporated by reference into this Item 1.01.

Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth in Item 1.01 hereof is incorporated by reference into this Item 2.03.

On September 22, 2025, the Company entered into the Indenture relating to the issuance by the Company of $500,000,000 aggregate principal amount of the 2033 Notes. The material terms and conditions of the Indenture and the 2033 Notes are as follows:

Maturity. The 2033 Notes mature on October 1, 2033, subject to earlier redemption or repurchase.

Interest. The 2033 Notes accrue interest at a rate of 5.875% per year. Interest on the 2033 Notes is paid semi-annually in arrears on April 1 and October 1, beginning on April 1, 2026.

Ranking. The 2033 Notes are the senior unsecured obligations of the Company.

Guarantees. Guardian Assets, Inc. initially guarantees the 2033 Notes, and each of the Company’s direct and indirect wholly-owned domestic subsidiaries that guarantees the Company’s U.S. senior secured credit facility will be required to guarantee the 2033 Notes.

Optional Redemption. The Company may redeem some or all of the 2033 Notes at any time prior to October 1, 2028, at a price equal to the sum of (a) 100% of the principal amount of the 2033 Notes being redeemed, (b) accrued and unpaid interest to, but excluding, the redemption date, and (c) a “make-whole” premium. The Company may redeem some or all of the 2033 Notes on or after October 1, 2028 at descending prices, starting at 102.938% of the principal amount of the 2033 Notes being redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. In addition, at any time prior to October 1, 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 interest to, but excluding, the redemption date.

Change of Control. Upon a 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 repurchase.

Covenants. The Indenture contains covenants limiting, among other things, the Company’s ability and the ability of the Company’s subsidiaries to:

•incur debt at subsidiaries that do not guarantee the 2033 Notes;

•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.
4.2						Form of Note for Amkor Technology, Inc.’s 5.875% Senior Notes due 2033 (incorporated by reference to Exhibit 4.1 hereof).
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.
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 N. Rogers

Mark N. Rogers

Executive Vice President, General Counsel, and Corporate Secretary

Date: September 22, 2025

AMKOR TECHNOLOGY, INC. 8-K