The state shall exercise its option under P.L. 104-193 to continue services to legal immigrants under temporary assistance for needy families, medicaid to the extent allowed by federal law, the state's basic health plan as provided in chapter
70.47 RCW, and social services block grant programs. Eligibility for these benefits for legal immigrants arriving after August 21, 1996, is limited to those families where the parent, parents, or legal guardians have been in residence in Washington state for a period of twelve consecutive months before making their application for assistance. Legal immigrants who lose benefits under the supplemental security income program as a result of P.L. 104-193 are immediately eligible for benefits under the state's general assistance-unemployable program. The department shall redetermine income and resource eligibility at least annually, in accordance with existing state policy.