N.Y. Soc. Serv. Law § 118

§ 118. Qualification on residence. The continuous residence required\nto acquire state residence or to establish liability for payment for\nhospital or other institutional care shall not include any period during\nwhich the person was (a) a patient in a hospital, or\n (b) an inmate of any public institution or any incorporated private\ninstitution, or\n (c) if a child under the age of twenty-one years, in a boarding home\nunder the care of an authorized agency, or\n (d) residing on any military reservation.\nIf, however, the periods of residence immediately prior and subsequent\nto the period specified in a, b, c, or d, shall together equal the\nrequired period of residence, such person shall be deemed to have had\nthe required continuous residence.\n