CMS Pub. 100-04, ch. 4, § 250.11

Under authority of 42 CFR 414.40, CMS establishes uniform national definitions of

services, codes to represent services, and payment modifiers to the codes. This includes

the use of payment modifiers for bilateral procedures.

Bilateral procedures rendered by a physician that has reassigned their billing rights to a

Method II CAH are payable by Medicare when the procedure is authorized as a bilateral

procedure and is billed on type of bill 85X with revenue code (RC) 96X, 97X or 98X and

the 50 modifier (bilateral procedure).

Modifier 50 applies to a bilateral procedure performed on both sides of the body during

the same operative session. When a procedure is identified by the terminology as bilateral

or unilateral, the 50 modifier is not reported.

If a procedure is authorized for the 150 percent payment adjustment for bilateral

procedures (payment policy indicator 1), the procedure shall be reported on a single line

item with the 50 modifier and one service unit. Modifiers LT (left side) and RT (right

side) shall not be reported when the 50 modifier applies. See §20.6 in this chapter for

more information on the use of the 50, LT and RT modifiers. See the Physician Fee

Schedule Payment Policy Record Layout in §250.2 for a description of the bilateral

procedure payment policy indicators.

If a procedure can be billed as bilateral, but is not authorized for the 150 percent bilateral

adjustment (payment policy indicator 3), the procedure shall be reported on a single line

item with the 50 modifier and one service unit.