Corporations use this form to determine whether the corporation is an applicable corporation under section 59(k) and to calculate corporate alternative minimum tax under section 55. Current revision Form 4626 PDF Instructions for Form 4626 (Print version PDF) Recent developments Treasury, IRS grant filing exception for tax-exempt organizations from filing new Form 4626, Alternative Minimum Tax - Corporations -- 23-OCT-2024 Partner’s instructions for Schedule K-1, Box 20, Code ZZ—CAMT -- 09-APRIL-2024 Corrections to the 2023 Form 4626, Alternative Minimum Tax - Corporations -- 14 -FEB-2024 Other items you may find useful All Form 4626 revisions Other current products Related items About Form 1120, U.S. Corporation Income Tax Return About Form 1120-C, U.S. Income Tax Return for Cooperative Associations About Form 1120-L, U.S. Life Insurance Company Income Tax Return About Form 1120-PC, U.S. Property and Casualty Insurance Company Income Tax Return About Form 3800, General Business Credit About Form 8827, Credit for Prior Year Minimum Tax - Corporations