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): ~~May~~June 611, 2026

ALLISON TRANSMISSION HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-35456

26-0414014

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)


One Allison Way, Indianapolis, Indiana		46222
(Address of principal executive offices)		(Zip Code)

Registrant’s telephone number, including area code: (317) 242-5000

Not Applicable

(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:

☐	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(s)

Name of each exchange

on which registered

Common Stock, $0.01 par value

ALSN

New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company 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 51.0201 ~~Departure~~Entry ofinto ~~Directors~~a orMaterial ~~Certain~~Definitive ~~Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers~~Agreement.

~~The~~On ~~Compensation~~June 11, ~~Committee~~2026, ~~(the “Committee”) of the Board of Directors of~~ Allison Transmission Holdings, Inc. (the “Company”), ~~previously~~Allison ~~approved~~Transmission, ~~the~~Inc., ~~Executive~~a ~~Change~~wholly-owned insubsidiary ~~Control~~of ~~and~~the ~~Severance~~Company ~~Plan~~ (the “~~Severance Plan~~Borrower”), ~~which~~Fairfield ~~provides~~Manufacturing ~~severance benefits to senior level employees of Allison Transmission~~Company, Inc., a wholly -owned subsidiary of the ~~Company~~Borrower (the “Subsidiary Guarantor”), and ~~designated~~Citibank, ~~Eric C~~N. ~~Scroggins~~A., ~~the~~as ~~Chief~~administrative ~~Legal~~agent ~~Officer~~(in ~~and~~such ~~Assistant~~capacity, ~~Secretary~~the of“Administrative ~~the~~Agent”) ~~Company,~~and as athe ~~Tier~~2026 ~~1/2~~refinancing ~~Participant~~term inlender, ~~the~~entered ~~Severance~~into ~~Plan.~~Amendment ~~On May~~No. 6, ~~2026,~~to ~~the~~Credit ~~Committee~~Agreement ~~approved~~(the ~~Mr. Scroggins’~~“Amendment”), ~~participation~~which inamends the ~~Severance~~Second ~~Plan~~Amended and Restated Credit Agreement, dated as aof ~~Tier~~March 29, 12019 ~~Participant.~~(as ~~The~~amended, ~~Severance~~restated, ~~Plan~~amended isand ~~listed~~restated, assupplemented anor ~~exhibit~~otherwise modified from time to ~~the~~time, ~~Company’s~~including ~~most~~as ~~recently~~amended ~~filed~~by ~~Annual~~the ~~Report~~Amendment, onthe ~~Form~~“Credit ~~10-K~~Agreement”).

~~Item~~The ~~5.07~~Amendment ~~Submission~~refinanced approximately $508 million of ~~Matters~~term toloan debt due March 13, 2031 and lowered the applicable margin on such refinanced loans by 0.25%, resulting in an interest rate margin that is, at the Borrower’s option, either (a) ~~Vote~~1.50% ofper ~~Security~~annum ~~Holders~~for SOFR Loans, or (b) 0.50% per annum for Base Rate Loans.

OnThe ~~May 6,~~foregoing ~~2026~~description does not purport to be complete and is subject to, ~~the~~and ~~Company~~qualified ~~held~~in its ~~annual~~entirety ~~meeting~~by, ofthe ~~stockholders.~~full Attext of the ~~annual meeting~~Amendment, ~~stockholders~~which ~~took~~is ~~the~~filed ~~following~~as ~~actions:~~Exhibit 10.1 hereto and incorporated herein by reference.

•Item ~~elected~~7.01 ~~nine~~Regulation ~~directors~~FD ~~for one-year terms ending at the 2027 annual meeting of stockholders (Proposal 1);~~Disclosure.

•On ~~ratified~~June 16, 2026, the ~~appointment~~Company ofissued ~~PricewaterhouseCoopers~~a ~~LLP~~press ~~(“PwC”)~~release asannouncing the ~~Company’s~~refinancing. ~~independent~~A ~~registered~~copy ~~public~~of ~~accounting~~the ~~firm~~press ~~for~~release ~~2026~~is ~~(Proposal~~attached ~~2);~~as Exhibit 99.1 hereto and is incorporated herein by reference.

•The ~~approved,~~information contained in anthis ~~advisory~~Item 7.01 and in Exhibit 99.1 hereto is furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, ~~non-binding~~as ~~vote~~amended (the “Exchange Act”), or otherwise subject to the ~~compensation~~liabilities ~~paid~~of that Section, nor shall it be deemed to be incorporated by reference into any filing of the Company’s ~~named~~under ~~executive~~the ~~officers~~Securities ~~(“Executive~~Act ~~Compensation”)~~of ~~(Proposal~~1933, 3)as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

~~The~~Item ~~vote~~9.01 ~~tabulation~~Financial ~~for~~Statements ~~each~~and ~~proposal follows:~~ Exhibits.

~~Proposal~~(d) ~~1 - Election of Directors~~Exhibits.

NOMINEES	FOR		AGAINST		ABSTAIN		BROKER NON-VOTES
Exhibit Number	Description
Judy L. Altmaier		71,134,529		1,454,365		375,889		4,902,906
10.1	Amendment No. 6 to Credit Agreement, dated as of June 11, 2026, among Allison Transmission Holdings, Inc., Allison Transmission, Inc., as borrower, Fairfield Manufacturing Company, Inc., as subsidiary guarantor, and Citibank, N.A., as administrative agent and as the 2026 refinancing term lender.
D. Scott Barbour		72,593,397		355,266		16,120		4,902,906
99.1	Press Release dated June 16, 2026.
Philip J. Christman		65,932,457		6,441,896		590,430		4,902,906
104	Cover Page Interactive Data File (embedded within the Inline XBRL document).
David C. Everitt		71,075,137		1,872,463		17,183		4,902,906
David S. Graziosi		71,830,548		1,116,804		17,431		4,902,906
Carolann I. Haznedar		71,744,480		1,190,862		29,441		4,902,906
Sasha Ostojic		72,863,411		84,133		17,239		4,902,906
Gustave F. Perna		72,609,598		339,201		15,984		4,902,906
Krishna Shivram		72,522,639		425,005		17,139		4,902,906

Proposal 2 - Ratification of Appointment of PwC.

FOR		AGAINST		ABSTAIN
77,162,806		690,303		14,580

Proposal 3 - Advisory Vote to Approve Executive Compensation.

FOR		AGAINST		ABSTAIN		BROKER NON-VOTES
70,176,855		2,759,179		28,749		4,902,906

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.

	Allison Transmission Holdings, Inc.
Date: May 8, 2026	By:	/s/ Eric C. Scroggins
Date: June 16, 2026	By:	/s/ Eric C. Scroggins
	Name:	Eric C. Scroggins
	Title:	Chief Legal Officer ~~and~~& Assistant Secretary

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