Pathology/Lab Coding Alert

Question: The lab receives an order for serum transcobalamin and performs a radiobinding assay. Should we use an unlisted chemistry code for this test?

Washington Subscriber

Answer: No, you should not use the unlisted chemistry code 84999 (Unlisted chemistry procedure) for this test.

Transcobalamin (TC) is the transport protein that binds vitamin B12 (Cyanocobalamin) in the blood and allows cellular uptake. Another name for a TC test is B12 binding capacity. The appropriate code for the test is 82608 (Cyanocobalamin (Vitamin B-12); unsaturated binding capacity).

Clarify: If the lab performs a test for holotranscobalamin (holoTC), you should report the unlisted code 84999. HoloTC identifies the portion of B12 that is bound to TC. CPT^® has deleted a Category III code (0103T, Holotranscobalamin, quantitative) for holoTC without a replacement Category I code.