Billing and Coding: MolDX: Short Tandem Repeat (STR) Markers and Chimerism (CPT® codes 81265-81268)
A57842
MolDX covers STR/chimerism testing to identify donors and to monitor engraftment or disease recurrence; CPT 81265 (recipient/donor testing) is covered and should be billed as 1 UOS and is generally limited to once per lifetime with case‑by‑case appeals for exceptions. CPT 81266 is covered for additional double‑cord blood samples in bone marrow transplants, CPT 81267 is covered post‑transplant for pre/post comparisons, and CPT 81268 is covered for buccal/germline recipient specimens post‑transplant; twin zygosity testing is statutorily excluded. Claims must include the appropriate CPT code with 1 UOS and the correct DEX Z‑Code in the specified claim fields (Part A and Part B) per the policy.
"Chimerism analysis to identify appropriate donors and to monitor post-transplant engraftment success or disease reoccurrence is a covered Medicare service."
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