CMS Pub. 100-04, ch. 16, § 90.3.1

Prior to January 1, 2018, when displaying claims payment for each CPT code in history,

A/B MACs (A) and (B) apply the following rules:

1. If all component tests of any panel are allowed because the individual line item

comparison is less than the fee (as determined in item C above), record the panel codes as

determined on the line-by-line comparison.

2. If all component tests are paid based on the panel price, allocate the current

payment proportionate to the amount submitted for each CPT code.

3. If any panel tests will be denied or there are previously paid automated laboratory

tests (as indicated by a check of beneficiary history), allocate the current payment amount

by allowed line proportionate to what was submitted for the current claim being

processed.

For administration of pricing requirements and/or invalid coding policies, A/B MACs (A)

and (B) must establish a processing sequence for concurrently processed claims based on

ascending order of internal control number (ICN). In the case of pricing, they must

process the “first claim” (i.e., lower CN) based solely on the billed codes on that claim,

process the “second” claim based on a combination of the billed codes on both claims

and pay the balance due after subtracting the amount paid on the “first” claim. In the

case of unacceptable code combinations, A/B MACs (A) and (B) must deny the “second”

claim.