42 CFR § 414.30 - Conversion factor update.
(a) General rule. The CF update for a CY equals the Medicare Economic Index increased or decreased by the number of percentage points by which the percentage increase in expenditures for physician services (or for a particular category of physician services, such as surgical services) in the second preceding FY over the third preceding FY exceeds the performance standard rate of increase established for the second preceding FY.
(b) Downward adjustment. The downward adjustment may not exceed the following:
(1) For CYs 1992 and 1993, 2 percentage points.
(2) For CY 1994, 2.5 percentage points.
(3) For CYs 1995 and thereafter, 5 percentage points.