D.C. Mun. Regs. tit. 14, § 6099
Annual Income -- the anticipated total income from all sources received by the head of household and spouse (even if temporarily absent) and by each additional member of the family, including all net income derived from assets, for the twelve (12) month period following the effective date of initial determination or reexamination of income, exclusive of income that is temporary, nonrecurring or sporadic, and exclusive of certain other types of income specified in paragraphs (b) and (c) of this definition.
(a) Annual Income includes, but is not limited to, the following:
(1) The full amount, before any payroll deduction, of wages and salaries, overtime pay, commissions, fees, tips, and bonuses, and other compensation for personal services;
(2) The net income from operation of a business or profession. Expenditures for business expansion or amortization of capital indebtedness shall not be used as deductions in determining net income. An allowance for depreciation of assets used in a business or profession may be deducted, based on straight line depreciation, as provided in Internal Revenue Service regulations. Any withdrawal of cash or assets from the operation of a business or profession will be included in income, except to the extent the withdrawal is reimbursement of cash or assets invested in the operation by the family;
(3) Interest, dividends, and other net income of any kind from real or personal property greater than $1,000 per year. Expenditures for amortization of capital indebtedness shall be used as deduction in determining net income. All allowance for depreciation is permitted only as authorized in paragraph (a)(2) of this definition. Net income from assets will be included in Annual Income for the purposes of this title if net income from assets exceeds $1,000. Notwithstanding this threshold, all assets with a value greater than $15,000 must be reported annually. Regardless of the value of the assets, imputed income from assets will not be included in Annual Income.