(a) The Medicaid agency must provide for a recorded individual plan of treatment and care to ensure that institutional care maintains the beneficiary at, or restores him to, the greatest possible degree of health and independent functioning.

(b) The plan must include—

(1) An initial review of the beneficiary's medical, psychiatric, and social needs—

(i) Within 90 days after approval of the State plan provision for services in institutions for mental disease; and

(ii) After that period, within 30 days after the date payments are initiated for services provided a beneficiary.

(2) Periodic review of the beneficiary's medical, psychiatric, and social needs;

(3) A determination, at least quarterly, of the beneficiary's need for continued institutional care and for alternative care arrangements;

(4) Appropriate medical treatment in the institution; and

(5) Appropriate social services.