What Is a Schedule K-1? A Schedule K-1 is a tax form used to report an individual’s share of income, deductions, credits, and other tax-related items from a pass-through entity. These forms are issued by different types of entities—such as partnerships (Form 1065)1 , S corporations (Form 1120-S)2, and estates or trusts (Form 1041)3 – The post What is a K-1 Tax Form?