(a) In general. Pensions and retirement allowances paid either by the Government or by private persons constitute gross income unless excluded by law. Usually, where the taxpayer did not contribute to the cost of a pension and was not taxable on his employer's contributions, the full amount of the pension is to be included in his gross income. But see sections 72, 402, and 403, and the regulations thereunder. When amounts are received from other types of pensions, a portion of the payment may be excluded from gross income. Under some circumstances, amounts distributed from a pension plan in excess of the employee's contributions may constitute long-term capital gain, rather than ordinary income.

(b) Cross references. For the inclusion of pensions in income for the purpose of the retirement income credit, see section 37 and the regulations thereunder. Detailed rules concerning the extent to which pensions and retirement allowances are to be included in or excluded from gross income are contained in other sections of the Code and the regulations thereunder. Amounts received as pensions or annuities under the Social Security Act (42 U.S.C. ch. 7) or the Railroad Retirement Act (45 U.S.C. ch. 9) are excluded from gross income. For other partial and total exclusions from gross income, see the following:

(1) Annuities in general, section 72 and the regulations thereunder;

(2) Employees' annuities, sections 402 and 403 and the regulations thereunder;

(3) References to other acts of Congress exempting veterans' pensions and railroad retirement annuities and pensions, section 122.