45 CFR 233.39 - Age.
(b) Federal financial participation.
(1) Federal financial participation is available in financial assistance provided to otherwise eligible persons who were, for any portion of the month for which assistance is paid:
(i) In OAA or AABD with respect to the aged, 65 years of age or over;
(ii) In AFDC, under 18 years of age; or age 18 if a full-time student in a secondary school, or in the equivalent level of vocational or technical training, and reasonably expected to complete the program before reaching age 19.
(iii) In AB or AABD with respect to the blind, any age;
(iv) In APTD or AABD with respect to the disabled, 18 years of age or older.
(2) Federal determination of whether an individual meets the age requirements of the Social Security Act will be made according to the common-law method (under which a specific age is attained the day before the anniversary of birth), unless the State plan specifies that the popular usage method (under which an age is attained on the anniversary of birth), is used.
(3) The State agency may adopt an arbitrary date such as July 1 as the point from which age will be computed in all instances where the month of an individual's birth is not available, but the year can be established.