42 CFR §482.60

1. (a)Be primarily engaged in providing, by or under the supervision of a doctor of medicine or osteopathy, psychiatric services for the diagnosis and treatment of mentally ill persons;
2. (b)Meet the conditions of participation specified in §§ 482.1 through 482.23 and §§ 482.25 through 482.57;
3. (c)Maintain clinical records on all patients, including records sufficient to permit CMS to determine the degree and intensity of treatment furnished to Medicare beneficiaries, as specified in § 482.61; and
4. (d)Meet the staffing requirements specified in § 482.62.