This Article summarizes and provides context to understand the most important developments in federal income taxation for the year 2020. The items discussed primarily consist of the following: (1) significant amendments to the Internal Revenue Code; (2) important judicial decisions; and (3) noteworthy administrative rulings and regulations promulgated by the Treasury Department and the Service. This Article primarily focuses on subjects of broad general interest--tax accounting rules, determination of gross income, allowable deductions, treatment of capital gains and losses, corporate and partnership taxation, exempt organizations, and procedure and penalties. This Article generally does not address items relating to federal estate and gift taxation, income taxation of trusts and estates, qualified pension and profit-sharing plans, international taxation, or specialized industries such as banking, insurance, and financial services.