(a) Alternate level of care services shall mean services provided by a hospital to a patient for whom it has been determined that hospital services are not medically necessary, but that skilled nursing or health-related services are medically necessary, and are being provided by the hospital and are not otherwise available.

(b) Commissioner shall mean the Commissioner of Mental Health.

(c) Hospital shall mean a facility providing inpatient care or treatment of persons with mental illness which has been issued an operating certificate by the Office of Mental Health pursuant to article 31 of the Mental Hygiene Law and in accordance with Part 582 of this Title. For purposes of this Part, the term hospital shall not include hospitals licensed pursuant to article 28 of the Public Health Law, residential treatment facilities for children and youth issued an operating certificate in accordance with Part 584 of this Title and hospitals within the Office of Mental Health.

(d) Medical Assistance Program shall mean the program of medical assistance to needy persons authorized under title 11 of article 5 of the Social Services Law, and regulations, as identified in section 502.2(d) of this Title, promulgated thereunder and title XIX of the Social Security Act, as identified in section 502.2(c) of this Title and regulations promulgated thereunder.

(e) Patient day shall mean the unit of measure denoting lodging provided and services rendered to one patient between the census-taking hour on two successive days. A patient day is counted on the day of admission but not on the day of discharge. A patient day is counted when a patient is admitted as an inpatient with the expectation of remaining overnight but is discharged on the same day.