45 CFR § 233.40 - Residence.
(a) Condition for plan approval. A State plan under title I, IV-A, X, XIV, or XVI of the Social Security Act may not impose any residence requirement which excludes any individual who is a resident of the State except as provided in paragraph (b) of this section. For purposes of this section:
(1) A resident of a State is one: (i) Who is living in the State voluntarily with the intention of making his or her home there and not for a temporary purpose. A child is a resident of the State in which he or she is living other than on a temporary basis. Residence may not depend upon the reason for which the individual entered the State, except insofar as it may bear upon whether the individual is there voluntarily or for a temporary purpose; or
(ii) Who, is living in the State, is not receiving assistance from another State, and entered the State with a job commitment or seeking employment in the State (whether or not currently employed). Under this definition, the child is a resident of the State in which the caretaker is a resident.
(2) Residence is retained until abandoned. Temporary absence from the State, with subsequent returns to the State, or intent to return when the purposes of the absence have been accomplished, does not interrupt continuity of residence.
(b) Exception. A State plan under title I, X, XIV, or XVI need not include an individual who has been absent from the State for a period in excess of 90 consecutive days (regardless of whether the individual has maintained his or her residence in the State during this period) until he or she has been present in the State for a period of 30 consecutive days (or a shorter period specified by the State) in the case of such individual who has maintained residence in the State during such period of absence or for a period of 90 consecutive days (or a shorter period as specified by the State) in the case of any other such individual. An individual thus excluded under any such plan may not, as a consequence of that exclusion, be excluded from assistance under the State's title XIX plan if otherwise eligible under the title XIX plan (see 42 CFR 436.403).
The following state regulations pages link to this page.