42 C.F.R. § 410.155
(a) Limitation. For services subject to the limitation as specified in paragraph (b) of this section, the percentage of the expenses incurred for such services during a calendar year that is considered incurred expenses under Medicare Part B when determining the amount of payment and deductible under § 410.152 and § 410.160 of this part, respectively, is as follows:
(b) Application of the limitation—(1) Services subject to the limitation. Except as specified in paragraph (b)(2) of this section, services furnished by physicians and other practitioners, whether furnished directly or incident to those practitioners' services, are subject to the limitation if they are furnished in connection with the treatment of a mental, psychoneurotic, or personality disorder (that is, any condition identified by a diagnosis code within the range of 290 through 319) and are furnished to an individual who is not an inpatient of a hospital:
(2) Services not subject to the limitation. Services not subject to the limitation include the following:
(3) Payment amounts. The Medicare payment amount and the patient liability amounts for outpatient mental health services subject to the limitation for each year during which the limitation is phased out are as follows:
| Calendar year | Recognized incurredexpenses | Patient pays | Medicare pays |
|---|---|---|---|
| CY 2009 and prior calendar years | 62.50% | 50% | 50% |
| CYs 2010 and 2011 | 68.75% | 45% | 55% |
| CY 2012 | 75.00% | 40% | 60% |
| CY 2013 | 81.25% | 35% | 65% |
| CY 2014 | 100.00% | 20% | 80% |
(c) General formula. A general formula for calculating the amount of Medicare payment and the patient liability for outpatient mental health services subject to the limitation is as follows:
[63 FR 20129, Apr. 23, 1998, as amended at 73 FR 69934, Nov. 19, 2008; 74 FR 62005, Nov. 25, 2009; 88 FR 82179, Nov. 22, 2023]