Examples of IHC coding

Q. You perform a biopsy by punch of an a typical pigmented lesion, single specimen processed into a single block A. HMB-45 stain performed as well as a separate stained slide using a Mib1-Mart1 antibody cocktail.

A. For commercial payers, you report:

        HMB-45 (slide 1) and Mib1-Mart1 cocktail (slide 2)

        88342 X 2                  88343 X 1    

        For Medicare, you report:

        HMB-45 (slide 1) and Mib1-Mart1 cocktail (slide 2)

        G0461 X 1                 G0462 X 2

Note: MIB/Mart is sequential staining with 2 kits, so each stain is billed separately. 

Q. A large excisional specimen is received of a previously biopsied dermatofibrosarcoma protuberans (DFSP), which due to the specimen size is processed into a total of10 separate tissue blocks. During histologic evaluation it is determined that the margins of the residual DFSP are indistinct in 4 of the blocks and therefore a CD34 stain is obtained on each of these 4 tissue blocks.

A. For commercial payers, you report:

        88342 X 4

        For Medicare, You report:

        G0461 X 1

Q. Punch biopsy of an atypical lymphoid infiltrate, single specimen processed into a single block A. CD4, CD8, CD20, and CD30 immunostaining are performed separate slides.

A. For Commercial Payer, you report:

        88342 X4     

        For Medicare, you report:

Because you have four separately identifiable stains on different slides (CD4, CD8, CD20 and CD30) from block A it is appropriate to report each slide individually as follows: 

        G0461 X1; G0462 X 3 

Q. A biopsy by punch technique of an a typical nevus on the back and another of the chest is performed. A Melan-A stain is performed on both specimens.

A: For Commercial Payers, your report:

        88342 X 2

        For Medicare, you report:

        G0461 X 2 

Q. Excisional biopsy of an atypical nevus of the back (one specimen processed into 3 tissue blocks, block A1, A2, and A3). A melan-A stain is performed on blocks A2 and A3.

A: For Commercial Payers, you report:

        88342 X 2 

        For Medicare, you report:

        Because a single Melan-Astain is performed on blocks A2 and A3 it is only appropriate to report G0461 x 1