MedicaidCoverageMedium impact
Thiopurine S-Methyltransferase Enzyme Activity Testing - MEDICAID - INDIANA (New)
Humana·IN · Gastroenterology, Oncology, Rheumatology +3 more·Pharmacy
Effective date
Jul 22, 2026
We identified it
Jul 23, 2026
Summary
Humana Indiana Medicaid now covers TPMT enzyme activity testing (CPT 84433) for two specific indications: to guide medication dosing before initiating thiopurine therapy (azathioprine, mercaptopurine, thioguanine) or to assess severe toxicity from existing thiopurine therapy. This is a new policy effective July 22, 2026, with special EPSDT review requirements for members under age 21.
Action Required
By July 22, 2026: Billing team must update billing system and encounter forms to recognize CPT 84433 as a covered service for Indiana Medicaid members. Configure system to accept claims only when documentation supports one of two approved indications: (1) pre-treatment dosing guidance for thiopurine medications, or (2) evaluation of severe toxicity from thiopurine therapy. For members under age 21, flag all requests for medical necessity review per EPSDT requirements before claim submission. Update coding guidelines and provider communication materials. Providers should document the specific indication in clinical notes to support medical necessity. Claims submitted without proper indication documentation or for members under 21 without EPSDT review may be denied.