Gross ncome Defined Section 61a defines gross income as all income from whatever source derived, including(but not limited to) the following items Compensation for services, fees commissions and similar items Gross income derived from business Gains from dealings in property InterestGross Income Defined • Section 61(a) defines gross income as “all income from whatever source derived,” including (but not limited to) the following items: – Compensation for services, fees, commissions, and similar items – Gross income derived from business – Gains from dealings in property – Interest