Tumor Chemosensitivity Assays — CPB 0245 | AETNA Coverage Update

Aetna modified CPB 0245 governing tumor chemosensitivity assays, effective September 26, 2025. Here's what billing teams need to know.

Aetna, a CVS Health company, updated Clinical Policy Bulletin 0245 covering tumor chemosensitivity assays — including DiSC (differential staining cytotoxicity) assays, 3D spheroid cultures, and cancer stem cell cytotoxicity testing. The CPB 0245 Aetna policy revision affects 22 CPT codes, including newer PLA codes like 0248U, 0511U, and 0525U, along with established tissue culture codes 88237 and 88239. If your practice or lab bills these assays for oncology patients under ICD-10 range C00.0–D49.9, audit your charge capture and prior authorization workflows before September 26, 2025.

Quick-Reference Table

Aetna Tumor Chemosensitivity Assay Coverage Criteria and Medical Necessity Requirements 2025

The core tension in Aetna's tumor chemosensitivity assay coverage policy is well-established: these tests have been around for decades, but payers have historically viewed most of them as not meeting medical necessity standards for routine oncology care. CPB 0245 continues that pattern.

The policy addresses whether in vitro testing of a patient's tumor cells against a panel of chemotherapy drugs — before treatment selection — is covered. The clinical argument is intuitive. If you can test which drugs kill a specific patient's tumor cells in a lab, you should be able to pick better treatment. Aetna's position, consistent with most major payers, is that the clinical evidence doesn't reliably show these tests improve patient outcomes over standard oncologist-guided selection.

For billing teams, this matters most when oncologists or labs order codes like 81535 and 81536 (gynecologic oncology live tumor cell culture by DAPI stain), 0248U (brain spheroid culture, 12-drug panel), or 0511U (solid tumor 3D microenvironment, 36+ drug panel). These are the codes most likely to generate a claim denial if documentation doesn't align with the coverage policy criteria.

The Aetna tumor chemosensitivity assay coverage policy also pulls in supporting pathology codes — 88305, 88313, 88358 — and cytopathology code 88104. These appear on claims alongside the primary assay codes. If the underlying assay is denied, these supporting codes often follow. Build that into your denial management expectations.

Prior authorization is worth confirming for any PLA code submission in this space. Codes 0248U, 0249U, 0435U, 0511U, and 0525U are all relatively new to the code set. Aetna's prior authorization requirements for newer oncology lab codes have tightened over the past two years. Don't assume prior auth isn't required just because an older version of the policy didn't flag it — verify with Aetna directly for each plan type before the effective date of September 26, 2025.

Reimbursement for these codes varies significantly by plan. Self-insured and fully-insured Aetna plans may have different coverage determinations. Always check the specific plan's coverage terms, not just the CPB.

Aetna Tumor Chemosensitivity Assay Exclusions and Non-Covered Indications

The codes in the "Differential staining cytotoxicity (DiSC) assay, Human tumor" group — which includes CPT codes 81535, 81536, 0248U, 0249U, 0435U, 0511U, 0525U, 0564T, and several supporting pathology codes — carry the highest risk of non-coverage under this CPB.

DiSC assays and their modern equivalents (3D spheroid cultures, cancer stem cell cytotoxicity assays) share the same evidentiary problem. Clinical studies have not consistently shown that using these assay results to guide chemo selection produces better survival outcomes than standard treatment protocols. Aetna uses that evidentiary gap to classify these as experimental or investigational.

The 0564T code — chemotherapeutic drug cytotoxicity assay of cancer stem cells — is a Category III CPT code. Category III codes carry inherent coverage risk with all payers, including Aetna. If your lab is billing 0564T, treat it as presumptively non-covered until you have written confirmation otherwise.

Code 0249U covers breast cancer semiquantitative phosphoprotein analysis. It sits in the DiSC assay group in this policy. That's a signal about how Aetna categorizes it — not as a standard diagnostic, but as part of the broader chemosensitivity testing bucket. Expect the same coverage scrutiny.

Codes 81462, 81463, and 81464 appear in this policy covering solid organ neoplasm genomic sequence analysis from cell-free nucleic acid (liquid biopsy). These are distinct from chemosensitivity assays clinically, but their inclusion here suggests Aetna is grouping certain advanced molecular oncology panels under this CPB. If you bill liquid biopsy panels under these codes for Aetna members, confirm they're not being adjudicated under CPB 0245 before assuming coverage.

Coverage Indications at a Glance

Aetna Tumor Chemosensitivity Assay Billing Guidelines and Action Items 2025

CPT, HCPCS, and ICD-10 Codes for Tumor Chemosensitivity Assays Under CPB 0245

DiSC Assay / Human Tumor — High Denial Risk Group

Other CPT Codes Related to CPB 0245

Key HCPCS Codes

Key ICD-10-CM Diagnosis Codes