Antero Midstream (NYSE: AM) prices upsized $600M 5.750% senior notes deal

Rhea-AI Filing Summary

Antero Midstream Corporation announced the pricing of a previously launched private placement of $600.0 million aggregate principal amount of 5.750% senior notes due 2034 issued by its subsidiaries Antero Midstream Partners LP and Antero Midstream Finance Corporation. The deal was upsized from an initial target of $500.0 million and is expected to close on December 23, 2025.

If Antero’s planned acquisition of HG Energy II Midstream Holdings LLC does not close by a contractually defined outside date, if the purchase agreement is terminated, or if Antero Midstream Partners concludes the acquisition will not occur, the issuer must redeem all of the notes at 100% of their initial issue price plus accrued and unpaid interest. Completion of the notes offering is not contingent on closing the HG acquisition or on the planned Utica Shale midstream asset disposition, and those transactions are not contingent on the notes offering.

Insights

Credit and capital structure analyst

Antero Midstream prices an upsized $600M notes deal tied to HG acquisition timing.

Antero Midstream priced a private placement of $600.0 million of 5.750% senior notes due 2034, upsized from $500.0 million. The notes are issued by indirect subsidiaries, which concentrates this new debt at the midstream partnership level rather than the parent. A fixed 5.750% coupon locks in long-term borrowing costs and adds scale to the company’s debt stack.

The notes include a special mandatory redemption if the HG Energy II Midstream Holdings acquisition does not close by a defined outside date between June 2, 2026 and no later than September 2, 2026, if the purchase agreement is terminated, or if Antero Midstream Partners reasonably determines the deal will not close. In that case, all outstanding notes must be redeemed at 100% of the initial issue price plus accrued interest.

The offering is not contingent on the HG acquisition or the Utica Shale midstream asset disposition, and those transactions are not contingent on the offering. This separation means the new capital can be raised regardless of deal timing, while the redemption feature provides a defined outcome for noteholders if the HG transaction does not proceed.

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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 9, 2025

ANTERO MIDSTREAM CORPORATION

(Exact Name of Registrant as Specified in its Charter)

Delaware		001-38075		61-1748605
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification Number)

1615 Wynkoop Street

Denver, Colorado 80202

(Address of Principal Executive Offices) (Zip Code)

Registrant’s Telephone Number, including area code (303) 357-7310

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, par value $0.01 Per Share		AM		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 8.01 Other Events.

On December 9, 2025, Antero Midstream Corporation (the “Company”) issued a press release, a copy of which is attached hereto as Exhibit 99.1 and incorporated herein by reference, announcing the pricing of the previously announced private placement (the “Offering”) of $600.0 million in aggregate principal amount of the Company’s indirect, wholly owned subsidiaries, Antero Midstream Partners LP (“Antero Midstream Partners”) and Antero Midstream Finance Corporation’s 5.750% Senior Notes due 2034 (the “Notes”). The Offering was upsized from an initial offering size of $500.0 million aggregate principal amount of the Notes. The Offering is expected to be completed on December 23, 2025.

However, if (i) the closing of the Company’s acquisition of HG Energy II Midstream Holdings, LLC from HG Energy II LLC (the “HG Acquisition”) has not occurred on or prior to the later of (x) June 2, 2026 and (y) such date to which the outside date under the Membership Interest Purchase Agreement, dated December 5, 2025, by and among by and among Antero Midstream Partners, Antero Resources Corporation, HG Energy II LLC, HG Energy II Production Holdings LLC and HG Energy II Midstream Holdings LLC (the “HG Purchase Agreement”) as in effect on the closing date of this offering may be extended in accordance with the terms thereof, which date shall be no later than September 2, 2026, any such extension to be set forth in an officers’ certificate delivered to the trustee prior to the close of business on June 2, 2026 or such other extended outside date as shall then be applicable (the “Special Mandatory Redemption Outside Date”), (ii) prior to the Special Mandatory Redemption Outside Date, the HG Purchase Agreement is terminated according to its terms without the closing of the HG Acquisition or (iii) Antero Midstream Partners determines based on its reasonable judgment that the HG Acquisition will not close prior to the Special Mandatory Redemption Outside Date or at all, Antero Midstream Partners will be required to redeem all of the outstanding Notes at a redemption price equal to 100% of the initial issue price of the Notes, plus accrued and unpaid interest, if any, to but excluding, the special mandatory redemption date.

The completion of the Offering is not contingent on the consummation of the HG Acquisition or the disposition of all the Company’s Utica Shale midstream assets (the “Utica Disposition”), and the HG Acquisition and the Utica Disposition are not contingent on the closing of the Offering.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

EXHIBIT		DESCRIPTION
99.1		Antero Midstream Corporation press release, dated December 9, 2025.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).

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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.

	ANTERO MIDSTREAM CORPORATION
	By:	/s/ Justin J. Agnew
		Justin J. Agnew
		Chief Financial Officer, Vice President – Finance & Investor Relations

Dated: December 9, 2025

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FAQ

What did Antero Midstream Corporation (AM) announce in this Form 8-K?

Antero Midstream Corporation announced the pricing of a private placement of $600.0 million aggregate principal amount of 5.750% senior notes due 2034 issued by its indirect, wholly owned subsidiaries.

How large is Antero Midstream Corporation’s new notes offering and how did it change from the initial size?

The offering totals $600.0 million in aggregate principal amount of 5.750% senior notes due 2034, upsized from an initial offering size of $500.0 million.

When is Antero Midstream’s $600 million notes offering expected to be completed?

The private placement of $600.0 million of 5.750% senior notes due 2034 is expected to be completed on December 23, 2025.

What is the special mandatory redemption feature tied to Antero Midstream’s HG Acquisition?

If the HG Energy II Midstream Holdings acquisition does not close by the defined outside date, if the purchase agreement is terminated, or if Antero Midstream Partners determines the deal will not close, all outstanding notes must be redeemed at 100% of the initial issue price plus accrued and unpaid interest to, but excluding, the special mandatory redemption date.

Are the HG Acquisition and Utica Shale asset disposition contingent on Antero Midstream’s notes offering?

No. Completion of the $600.0 million notes offering is not contingent on the HG Acquisition or the Utica Shale midstream asset disposition, and those transactions are not contingent on the closing of the notes offering.

Who is issuing the 5.750% senior notes mentioned by Antero Midstream Corporation (AM)?

The 5.750% senior notes due 2034 are being issued by Antero Midstream Corporation’s indirect, wholly owned subsidiaries, Antero Midstream Partners LP and Antero Midstream Finance Corporation.