(a) This Subpart shall govern Medicaid rates of payments for ambulatory care services provided in the following categories of facilities for the following periods:

1. (1) outpatient services provided by general hospitals on and after December 1, 2008;
2. (2) emergency department services provided by general hospitals on and after January 1, 2009;
3. (3) ambulatory surgery services provided by general hospitals on and after December 1, 2008;
4. (4) ambulatory services provided by diagnostic and treatment centers on and after September 1, 2009;
5. (5) ambulatory surgery services provided by free-standing ambulatory surgery centers on and after September 1, 2009; and

6. (6) hospital-based mental hygiene services on and after July 1, 2010, including:

   1. (i) mental retardation clinics;
   2. (ii) mental health clinics;
   3. (iii) alcoholism and drug abuse clinics and outpatient rehabilitation; and
   4. (iv) methadone clinics.

(b) Notwithstanding subdivision (a) of this section, the provisions of this Subpart shall not apply to the following:

1. (1) facilities whose Medicaid reimbursement is governed by subdivision 8 of section 2807 of the Public Health Law, except when the provisions of this Subpart are made applicable pursuant to paragraph (f) of such subdivision; and
2. (2) payments made on behalf of persons enrolled in Medicaid managed care or in the family health plus program.