Tumor In Vitro Chemosensitivity and Chemoresistance Assays - (0203) | CIGNA Coverage Update

Summary: Cigna Healthcare modified its coverage policy for tumor in vitro chemosensitivity and chemoresistance assays, effective April 16, 2026. Here's what billing teams need to know before claims start hitting the wall.

Cigna Healthcare — that's the full name on the policy document — updated policy 0203 governing tumor in vitro chemosensitivity and chemoresistance assay coverage. This policy has historically treated these assays as experimental or investigational, and the April 16, 2026 effective date makes this a live issue right now. The policy document does not list specific CPT or HCPCS codes, which creates its own set of billing problems we'll address below.

Quick-Reference Table

Cigna Tumor Chemosensitivity Assay Coverage Policy: Medical Necessity Requirements 2026

The Cigna in vitro chemosensitivity and chemoresistance assay coverage policy under 0203 addresses one of the more contested areas in oncology billing. The core question these assays try to answer — which chemotherapy drug will work best for a specific patient's tumor — sounds clinically useful. Cigna's long-standing answer has been that the evidence doesn't support routine reimbursement for guiding treatment decisions.

In vitro chemosensitivity assays test a patient's tumor cells in a lab setting. The assay exposes those cells to different chemotherapy agents and measures how sensitive or resistant the cells are. The idea is to use those results to pick the most effective regimen for that individual patient.

Cigna has classified these assays as experimental and investigational under this coverage policy for years. The 0203 modification effective April 16, 2026 doesn't reverse that position. What changes with a "modified" designation is typically the policy language, criteria language, or supporting evidence review — not a wholesale flip to covered status. If your oncology billing team was hoping this update unlocked reimbursement, it almost certainly did not.

Medical necessity under Cigna generally requires that a service be proven safe and effective through peer-reviewed clinical evidence. For chemosensitivity assays, Cigna's position has been that the clinical utility — meaning whether acting on these test results actually improves patient outcomes — hasn't been established to their standard. That's the central medical necessity argument your team will face on any claim for these assays.

Prior authorization requests for experimental or investigational services under Cigna typically go nowhere, but some practices attempt prior auth as a coverage inquiry. Don't count on prior authorization approval for chemosensitivity assays under this policy. The experimental designation means the door is closed at the coverage level, not the authorization level.

Cigna Chemosensitivity Assay Exclusions and Non-Covered Indications

Cigna's policy 0203 treats in vitro chemosensitivity and chemoresistance assays as experimental and investigational across the board. That means no covered indications for routine use.

The policy applies to assays used to guide selection of chemotherapy for solid tumors and hematologic malignancies. Whether the assay is performed on a freshly resected tumor, a biopsy specimen, or circulating tumor cells, the coverage position is the same: not covered.

This is different from companion diagnostic tests that the FDA has approved to determine eligibility for a specific targeted therapy. Those tests — think HER2 testing for trastuzumab eligibility — operate under separate policies and different clinical frameworks. Don't conflate chemosensitivity assays with companion diagnostics. They're different categories with very different coverage outcomes at Cigna.

Functional profiling assays that assess tumor drug response fall into the same experimental bucket. If a lab markets a test as "personalized chemotherapy selection" or "tumor response profiling," assume it falls under 0203 and carries no Cigna coverage until proven otherwise.

Coverage Indications at a Glance

Note: The policy document for 0203 does not list specific CPT or HCPCS codes. See the Affected Codes section below.

Cigna Chemosensitivity Assay Billing Guidelines and Action Items 2026

The absence of specific codes in the 0203 policy document doesn't protect you from denials. It just means you need to do more work upfront to identify which codes your lab or oncology practice is using that fall under this policy's scope.

CPT, HCPCS, and ICD-10 Codes for Tumor In Vitro Chemosensitivity Assays Under Cigna Policy 0203

The Cigna 0203 policy document does not list specific CPT, HCPCS, or ICD-10 codes. This is a significant gap for billing teams.

When a payer policy doesn't name the codes it governs, the burden falls on your practice or lab to map your code set to the policy scope. That means reading the policy criteria and asking: does this service — whatever code we use to bill it — match what this policy describes?

What To Do Without a Code List

Reach out to Cigna's provider services line and request written confirmation of which CPT or HCPCS codes fall under policy 0203. Get it in writing. If Cigna's representative can't give you a code list, ask for a coverage determination for the specific codes your lab uses.

Document that call with date, representative name, and reference number. If you later get a claim denial that cites 0203, that documentation supports your appeal and shows your practice acted in good faith.

Codes Typically Associated With Chemosensitivity Testing (For Reference — Verify Against Your Specific Claims)

Because the policy doesn't list codes, we're not including a fabricated code table here. What we can tell you is this: your lab billing team likely uses codes in the molecular pathology Tier 1 or Tier 2 CPT range, or possibly proprietary lab test codes under HCPCS. Pull your own data. Don't rely on a blog post to define your code set when Cigna itself won't.