Cardiology Coding Alert

Question: Does it matter whether we report 93971-LT, 93971-RT for a service instead of 93970?

Connecticut Subscriber

Answer: The appropriate code for the bilateral service is 93970 (Duplex scan of extremity veins including responses to compression and other maneuvers; complete bilateral study). You should report one unit of this code, and you should not append modifier 50 (Bilateral service) because the code descriptor states that the code is for a bilateral service. Medicare payment, at a national non-facility rate of $200.51, already takes the bilateral nature of the service into account.

You should not append RT (Right side) and LT (Left side) to 93971 (Duplex scan of extremity veins including responses to compression and other maneuvers; unilateral or limited study) to indicate a bilateral service. When you have a specific code for the bilateral service, then coding the unilateral services individually would not be compliant coding.

As an added incentive, if you report 93971 with RT and LT on the same claim, you’re likely to receive only the amount for a single unit of 93971, $123.25 at the national Medicare nonfacility rate. The Medicare Physician Fee Schedule gives 93971 a bilateral indicator of 0, which includes this rule in the definition: “base the payment for the two sides on the lower of: (a) the total actual charge for both sides or (b) 100% of the fee schedule amount for a single code.”

Warning: Part B MAC National Government Services recently reported an increase in coding errors for procedures that may be either unilateral or bilateral: “Bilateral services should not be reported on 2 separate claim forms or as 2 lines of service with a 50 modifier on the second line item.”

Don’t try separate claims: The MAC indicated that use of 93970 is the correct way to bill for the bilateral service and that an example of incorrect billing is assigning 93971 “on separate claims including the LT modifier for the left side, and RT modifier for the right. Billing separately for left and right in this manner results in an overpayment from the Medicare Trust Fund, and is not the appropriate way to bill for these procedures.”

Overpayments can of course lead to refund requests upon review, so be sure to code correctly to avoid having to return money to the payer.