Clarification on Coding for IHC

The 2014 CPT book includes a revision to 88342 and addition of code 88343. Their descriptions are as follows:

• 88342 - Immunohistochemistry or immunocytochemistry, each separately identifiable antibody per block, cytologic preparation, or hematologic smear; first separately identifiable antibody per slide

(Do not report 88342 in conjunction with 88360 or 88361 for the same antibody)
(For quantitative or semiquantitative immunohistochemistry, see 88360, 88361)

• 88343…each additional separately identifiable antibody per slide (List separately in addition to code for primary procedure)

CMS disagreed with the AMA’s descriptors of 88342 and 88343 in their PFS Final Rule and created two new “G” codes. For a Medicare, Medicaid or Tricare beneficiary, the focus will not be per block but will be per antibody, per specimen. These new codes are:

• G0461 (Immunohistochemistry or immunocytochemistry, per specimen; first single or multiplex antibody stain) and
• G0462 (Immunohistochemistry or immunocytochemistry, per specimen; each additional single or multiplex antibody stain (List separately in addition to code for primary procedure)

For examples of proper application of each code, please refer to APS’ white paper, distributed in January.  Also, as a reminder, APS would like all clients to continue to CPT code all IHC stains using 88342/88343 codes and units of service.  APS has written an edit to identify cases with financial classes indicating government payors and will submit the appropriate “G” codes and units of service for those claims.  If you have any additional questions, please contact your Practice Manager.