Who Must File

Generally, the following apply.

• A domestic corporation or group of corporations required to file Form 1120, U.S. Corporation Income Tax Return, that reports on Form 1120, Schedule L, Balance Sheets per Books, total assets at the end of the corporation's tax year that equal or exceed $10 million must file Schedule M-3 instead of Schedule M-1, Reconciliation of Income (Loss) per Books With Income per Return.

• A corporation filing a non-consolidated Form 1120 that reports on Schedule L total assets that equal or exceed $10 million must complete and file Schedule M-3 and must check box (1) Non-consolidated return, at the top of page 1 of Schedule M-3.

• A corporation filing Form 1120 (or Form 1120-C) that is not required to file Schedule M-3 may voluntarily file Schedule M-3.

• If a corporation was required to file Schedule M-3 for the preceding tax year, but reports on Form 1120, page 1, item D, and on Form 1120, Schedule L, total consolidated assets at the end of the current tax year of less than $10 million, the corporation is not required to file Schedule M-3 for the current tax year.

See Completing Schedule M-3, later.

In the case of a U.S. consolidated tax group, total assets at the end of the tax year must be determined based on the total year-end assets of all includible corporations listed on Form 851, net of eliminations for intercompany transactions and balances between the includible corporations. In addition, for purposes of determining whether the corporation (or U.S. consolidated tax group) has total assets at the end of the current tax year of $10 million or more, the corporation's total consolidated assets must be determined on an overall accrual method of accounting unless both of the following apply: (a) the tax returns of all includible corporations in the U.S. consolidated tax group are prepared using an overall cash method of accounting, and (b) no includible corporation in the U.S. consolidated tax group prepares or is included in financial statements prepared on an accrual basis.

Special Filing Requirements for Certain Groups

Mixed groups. If the parent corporation of a U.S. consolidated tax group files Form 1120 and files and completes Schedule M-3, Parts II and III, then Schedule M-3, Parts II and III, must be completed for each member of the group. However, if the parent corporation of a U.S. consolidated tax group files Form 1120 and any member of the group files Form 1120-PC, U.S. Property and Casualty Insurance Company Income Tax Return, or Form 1120-L, U.S. Life Insurance Company Income Tax Return, that member must complete Parts II and III of Schedule M-3 (Form 1120-PC) or Schedule M-3 (Form 1120-L),

Instructions for Schedule M-3 (Form 1120) (Rev. 6-2025) Catalog Number 38103Y Jun 26, 2025 Department of the Treasury Internal Revenue Service www.irs.gov

respectively, and the group must comply with the mixed group consolidated Schedule M-3 instructions under Schedule M-3 Consolidation for Mixed Groups (1120/L/PC), later. A mixed group must also file Form 8916, Reconciliation of Schedule M-3 Taxable Income With Tax Return Taxable Income for Mixed Groups, and, if applicable, Form 8916-A, Supplemental Attachment to Schedule M-3.

If the parent company of a U.S. consolidated tax group files Form 1120 and any member of the group files Form 1120-PC or Form 1120-L and the consolidated Schedule L reported in the return includes the assets of all of the companies (the insurance companies as well as the non-insurance companies), in order to determine if the group meets the $10 million threshold test for the requirement to file Schedule M-3, use the amount of total assets reported on Schedule L of the consolidated return. If the parent company of a U.S. consolidated tax group files Form 1120 and any member of the group files Form 1120-PC or Form 1120-L and the consolidated Schedule L reported in the return does not include the assets of one or more of the insurance companies in the U.S. consolidated tax group, in order to determine if the group meets the $10 million threshold test, use the sum of the amount of total assets reported on the consolidated Schedule L plus the amounts of all assets reported on Forms 1120-PC and 1120-L that are included in the consolidated return but not included on the consolidated Schedule L.

Other entities. There are unique separate Schedules M-3 for taxpayers required to file Form 1065, U.S. Return of Partnership Income; Form 1120-S, U.S. Income Tax Return for an S Corporation; Form 1120-F, U.S. Income Tax Return of a Foreign Corporation; and for Forms 1120-PC or 1120-L. For more information, see the instructions for the applicable Schedule M-3.

For insurance companies included in the consolidated U.S. income tax return, see the instructions for Part I, lines 10 and 11, and Part II, line 7, for guidance on Schedule M-3 reporting of intercompany dividends and statutory accounting adjustments.

No Schedule M-3 is required for taxpayers filing Form 1120-REIT, U.S. Income Tax Return for Real Estate Investment Trusts; Form 1120-RIC, U.S. Income Tax Return for Regulated Investment Companies; Form 1120-H, U.S. Income Tax Return for Homeowners Associations; and Form 1120-SF, U.S. Income Tax Return for Settlement Funds (Under Section 468B).