VIVMARK RESIDENTIAL

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

OR

Commission File Number:1-12252 (Vivmark Residential)

Commission File Number:0-24920 (ERP Operating Limited Partnership)

(Exact name of registrant as specified in its charter)

Equity Residential (Vivmark Residential) / Not applicable (ERP Operating Limited Partnership)

(Former name, former address and former fiscal year, if changed since last report)

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

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Vivmark Residential:

l

ERP Operating Limited Partnership:

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.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

The number of VMRK Common Shares of Beneficial Interest, $0.01 par value, outstanding on October 30, 2026 was 774,798,545.

(1)

On August 17, 2026, in connection with ERP Operating Limited Partnership's repayment at maturity of all of its outstanding 7.57% Notes due August 15, 2026 (the "Notes"), New York Stock Exchange LLC filed a Form 25 with the U.S. Securities and Exchange Commission to complete the delisting of the Notes from The New York Stock Exchange, which delisting became effective on August 27, 2026. The deregistration of the Notes under Section 12(b) of the Act will be effective 90 days, or such shorter period as the U.S. Securities and Exchange Commission may determine, after filing of the Form 25.

EXPLANATORY NOTE

On August 17, 2026 (the "Merger Date"), AvalonBay Communities, Inc., a Maryland corporation ("AvalonBay"), Equity Residential, a Maryland real estate investment trust ("Equity Residential"), ERP Operating Limited Partnership, an Illinois limited partnership (“ERPOP”), and Canopy Merger Sub LLC, a Maryland limited liability company and a direct wholly owned subsidiary of Equity Residential (“Merger Sub”), completed the transactions contemplated by the Agreement and Plan of Merger (the “Merger Agreement”). Pursuant to the Merger Agreement, (i) AvalonBay contributed certain assets to ERPOP in exchange for units of partnership interest in ERPOP that had, in the aggregate, a value equal to the fair market value of such contributed assets (the "Asset Contribution") and (ii) following the Asset Contribution, AvalonBay merged with and into Merger Sub, with Merger Sub surviving as a direct, wholly owned subsidiary of Equity Residential (the “Merger”). Following the Merger, Equity Residential contributed all of the membership interests of Merger Sub to ERPOP, and Merger Sub then merged with and into ERPOP, with ERPOP continuing as the surviving entity. On the Merger Date, Equity Residential was renamed Vivmark Residential ("Vivmark"). At the effective time of the Merger, each outstanding share of AvalonBay common stock was automatically cancelled and converted into the right to receive 2.793 common shares ("Common Shares") of Vivmark (the “Exchange Ratio”), plus the right, if any, to receive cash in lieu of fractional Common Shares. As a result, former AvalonBay stockholders and Equity Residential shareholders owned approximately 51% and 49% of Vivmark, respectively. The Merger was accounted for as a reverse acquisition, whereby Equity Residential was the legal acquirer and AvalonBay was the accounting acquirer. As a result, the Company’s historical financial statements for periods before the Merger Date are those of AvalonBay and share and per share amounts for those periods have been retroactively adjusted to reflect the Exchange Ratio.

This report combines the reports on Form 10-Q for the quarterly period ended September 30, 2026 of Vivmark and ERPOP. Equity Residential’s results of operations are included only from the Merger Date. Unless stated otherwise or the context otherwise requires, references to the “Company,” “we,” “us” or “our” mean collectively Vivmark, ERPOP and the entities and subsidiaries owned or controlled by Vivmark and/or ERPOP. References to the “Operating Partnership” mean collectively ERPOP and the entities and subsidiaries owned or controlled by ERPOP. The following chart illustrates the Company’s and the Operating Partnership’s corporate structure:

Vivmark is the sole general partner of ERPOP (“General Partner”) and, as of September 30, 2026, owned an approximate 98.7% ownership interest in ERPOP. References to "General Partner Capital" and "General Partner Units" represent Vivmark's ownership interest in ERPOP. Approximately 1.3% is owned by ERPOP's limited partners ("Limited Partners"). References to "Limited Partner Capital" and "Limited Partner Units" represent Limited Partners' interests in ERPOP. As the General Partner, Vivmark has exclusive control of ERPOP’s day-to-day management. Management operates Vivmark and ERPOP as one business, and the officers who manage Vivmark also manage ERPOP.

Vivmark and ERPOP are structured as an umbrella partnership REIT (“UPREIT”). Vivmark contributes the net proceeds from its equity offerings to ERPOP. In exchange, Vivmark receives partnership interests in ERPOP (“OP Units”) equal in number to the Common Shares issued, or, for any preferred share offerings, preference units with economic terms substantially the same as the related preferred shares. The UPREIT structure allows ERPOP to acquire communities in exchange for OP Units, which may, in certain circumstances, allow sellers to defer some or all of the taxable income or gain they would otherwise recognize on the sale. Under ERPOP’s partnership agreement, Limited Partners may tender their OP Units for redemption for Common Shares on a one-for-one basis or, at Vivmark’s election, cash. Under ERPOP’s partnership agreement, Vivmark and ERPOP maintain a one-for-one relationship between the OP Units held by Vivmark and Vivmark’s outstanding Common Shares.

The Company believes that combining the reports on Form 10-Q of Vivmark and ERPOP into this single report provides the following benefits:

• enhances investors’ understanding of Vivmark and the Operating Partnership by enabling investors to view the business as a whole in the same manner as management views and operates the business;

• eliminates duplicative disclosure and provides a more streamlined and readable presentation since a substantial portion of the disclosure applies to both Vivmark and the Operating Partnership; and

• creates time and cost efficiencies through the preparation of one combined report instead of two separate reports.

All of the Company’s community ownership, operations, development, redevelopment and any other activity are conducted through the Operating Partnership, which holds the Company’s assets, including its interests in joint ventures, and has no publicly traded equity. Vivmark’s primary function is acting as the General Partner of ERPOP. Vivmark has no assets or liabilities other than its investment in ERPOP, and it has no indebtedness because all debt is incurred by the Operating Partnership. Other than the net proceeds from Vivmark’s equity offerings, which Vivmark is obligated to contribute to ERPOP in exchange for OP Units or preference units, the Operating Partnership generates the capital required by the business. Its sources include working capital, net cash provided by operating activities, borrowings under its Unsecured Revolving Credit Facilities and Commercial Paper Program (see definitions in Note 7, "Debt" of the Consolidated Financial Statements), issuances of secured and unsecured debt and partnership interests, and proceeds from dispositions of communities and joint venture interests.

The main differences between the consolidated financial statements of the Company and those of the Operating Partnership are in shareholders’ equity, partners’ capital, noncontrolling interests, and per-share versus per-unit earnings. Vivmark issues Common Shares and preferred shares, while ERPOP issues OP Units and preference units. Limited Partners’ OP Units are presented as noncontrolling interests in the Company’s financial statements and as Limited Partner Capital in the Operating Partnership’s financial statements. In both sets of statements, noncontrolling interests include unaffiliated partners’ interests in consolidated partnerships.

To help investors understand these differences, this report provides separate consolidated financial statements for the Company and the Operating Partnership; a single set of notes that includes separate discussions of each entity’s noncontrolling interests, shareholders’ equity or partners’ capital, and earnings per share or per unit; and a combined Management’s Discussion and Analysis of Financial Condition and Results of Operations that includes discrete information for each entity.

Sections of this report that apply to only Vivmark or only the Operating Partnership refer to that entity specifically. Sections that combine disclosure for both entities generally describe actions, holdings and obligations as those of the Company. Although the Operating Partnership, directly or through its subsidiaries, generally enters into contracts and joint ventures and holds the assets and debt, management operates Vivmark and the Operating Partnership as one business, and conducts that business through the Operating Partnership.

This report also includes separate Part I, Item 4, Controls and Procedures, sections and separate Exhibit 31 and 32 certifications for each of the Company and the Operating Partnership, as required by Rules 13a-14 and 13a-15 or Rules 15d-14 and 15d-15, as applicable, of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and 18 U.S.C. §1350.

As the General Partner of ERPOP, Vivmark consolidates ERPOP for financial reporting purposes, and Vivmark has no assets or liabilities other than its investment in ERPOP. Therefore, the assets and liabilities of the Company and the Operating Partnership are the same on their respective financial statements. The separate discussions of Vivmark and the Operating Partnership in this report should be read in conjunction with each other to understand the consolidated results of the Company and how management operates it.