MolDX's New Hereditary Thrombophilia LCD Takes Effect October 12: What Labs Must Change
Short answer: On October 12, 2026, all four MolDX contractors begin applying a new LCD, "MolDX: Genetic Testing for Hereditary Thrombophilia." It replaces a long-standing non-coverage policy with limited coverage for specific VTE scenarios, but only for tests that pass a MolDX technical assessment. Any thrombophilia panel that includes MTHFR variants is not covered.
What changed, and when
The Medicare Coverage Database lists four final LCDs with the same title, "MolDX: Genetic Testing for Hereditary Thrombophilia," one per MolDX contractor: L40238 (Palmetto GBA), L40242 (Noridian), L40259 (CGS), and L40274 (WPS). Each shows an original effective date for services performed on or after October 12, 2026, and was last updated August 21, 2026. The Noridian version lists a notice period of August 27 through October 11, 2026, and notes the request was MAC initiated.
The legacy policy is being retired in step. Noridian's L36155, "MolDX: Genetic Testing for Hypercoagulability / Thrombophilia (Factor V Leiden, Factor II Prothrombin, and MTHFR)," carries an anticipated retirement date of October 11, 2026, the day before the new LCD takes effect. As of October 2, the MCD still showed no retirement date on the parallel legacy LCDs from Palmetto (L36089), CGS (L35984), and WPS (L36400). Watch for those listings to update, and do not assume the old and new policies will both apply to the same date of service.
From non-coverage to limited coverage
The old LCD was blunt. WPS's L36400 describes itself as "a non-coverage policy" for Factor V Leiden (F5), prothrombin G20210A (F2), and MTHFR testing for "all risk factors, signs, symptoms, diseases, or conditions," with a narrow carve-out for pregnant patients handled through appeal. It added that Medicare "may consider coverage" for F5 or F2 testing in unusual circumstances, but only on appeal and only when ordered by clinicians with formal hematology, hematopathology, or coagulation training. In practice, most claims denied and labs fought them one at a time.
The new LCD flips the default for defined indications. Its stated scope covers lab-developed tests, FDA-cleared and FDA-approved tests, and NGS tests for hereditary germline thrombophilia. The rationale leans heavily on the 2023 American Society of Hematology (ASH) thrombophilia testing guidelines, which evaluated testing across 23 clinical scenarios.
Who is covered under the new LCD
Per L40242, testing is covered only when all requirements are met. The patient must fit one of three clinical pictures:
- VTE associated with a non-surgical major transient or hormonal risk factor, as defined in ASH guidelines.
- Cerebral or splanchnic venous thrombosis, where short-term treatment is standard and testing will inform whether to continue anticoagulation long term.
- A current cancer diagnosis with ambulatory systemic therapy, low or intermediate VTE risk on a validated risk tool, and a first-degree relative with VTE.
Beyond the clinical picture, results must guide VTE management, such as starting or extending anticoagulation. The patient must not have had the same or a similar test for the same indication, consistent with MolDX's repeat germline testing policy (L38351). And the test must have completed a MolDX technical assessment.
Two things the LCD explicitly does not do. It does not cover screening of asymptomatic people with VTE risk factors, which it says is outside the LCD process. And while it acknowledges ACOG guidance on pregnancy, it notes that indication applies to a minority of Medicare patients.
The MTHFR rule is the operational trap
The analysis section is unambiguous: "any thrombophilia testing panels that include MTHFR variants will not be covered by this policy." The LCD cites ASH and others for the conclusion that MTHFR 677C>T and 1298A>C polymorphisms are not associated with VTE. This is stricter than simply not paying for the MTHFR line. A bundled F5, F2, and MTHFR order, which is how many hospital and reference labs have built their thrombophilia offering, falls outside coverage as a panel.
The LCD also sets content rules in both directions. A test must include at least the minimum genetic content with definitive guidelines-based evidence for its intended use, and must not include unvalidated content or content of unclear clinical validity or utility. Single-variant testing is acceptable only when it is the only reasonable test, such as a known familial variant. The LCD notes that protein C, protein S, and antithrombin deficiencies are usually assessed by functional assays, and that this policy covers genetic testing only.
What labs and RCM teams should do before October 12
Audit your test menu. List every orderable that touches F5, F2, or MTHFR. If your standard thrombophilia panel includes MTHFR, decide whether to offer a separate MTHFR-free genetic panel for Medicare patients, and update order forms so clinicians cannot select the bundled version by default.
Confirm technical-assessment status. Coverage depends on a completed MolDX technical assessment. If your test has not been through one, expect denials regardless of indication, and start the submission now. Make sure the billed test carries the right registered identifier, as covered in our DEX Z-code guide.
Rebuild the documentation packet. The covered scenarios are specific: provoked VTE with a non-surgical transient or hormonal factor, cerebral or splanchnic thrombosis, or the cancer-plus-family-history pathway. Requisitions and EHR order sets should capture the scenario, the planned management decision, and prior testing history. Our denial-prevention guide and our overview of Medicare coverage for genetic testing explain how LCD criteria translate into documentation.
Check repeat testing. Many patients have prior F5 or F2 results from years ago. Under the new LCD, a prior same or similar test for the same indication blocks coverage, so build a lookup before accessioning.
Use ABNs where appropriate. Orders for asymptomatic screening, MTHFR, or panels with MTHFR fall outside coverage. Follow your compliance team's Advance Beneficiary Notice process for those orders rather than billing and hoping.
Teams that want order-time criteria checks can see how ScreenMyGene maps tests to payer policy on our platform page.
FAQ
When does the new MolDX thrombophilia LCD take effect?
For services performed on or after October 12, 2026. The four contractor versions are L40238 (Palmetto), L40242 (Noridian), L40259 (CGS), and L40274 (WPS). Noridian's legacy LCD L36155 carries an anticipated retirement date of October 11, 2026. Confirm the policy that applies in your jurisdiction on the date of service.
Is MTHFR testing covered under the new LCD?
No. The LCD states that any thrombophilia testing panel that includes MTHFR variants will not be covered. It cites evidence that MTHFR 677C>T and 1298A>C polymorphisms are not associated with venous thromboembolism. Labs that bundle MTHFR with Factor V Leiden and prothrombin should offer an MTHFR-free option.
Which patients qualify for coverage?
Patients with VTE tied to a non-surgical major transient or hormonal risk factor; patients with cerebral or splanchnic venous thrombosis where testing informs long-term anticoagulation; and certain ambulatory cancer patients with low or intermediate VTE risk and a first-degree relative with VTE. Results must guide VTE management in every case.
Does my test need a MolDX technical assessment?
Yes. Satisfactory completion of a MolDX technical assessment is one of the coverage criteria, alongside clinical indication, guideline-based gene content, no unvalidated content, and no prior same or similar test for the same indication. Without it, claims should be expected to deny even when the patient meets clinical criteria.
Does the LCD cover screening family members?
No. The LCD says screening of individuals without illness or injury is outside the scope of the LCD process. Testing asymptomatic relatives, including for pregnancy planning, is not covered by this policy. Single-variant testing for a known familial variant is addressed only within the covered clinical scenarios.
This article is provided for general educational and business-decision-support purposes for laboratory, revenue-cycle, and clinical-ordering professionals. It summarizes Medicare Coverage Database documents as they appeared on October 2, 2026, and is not legal, coding, compliance, or reimbursement advice. Coverage policies change; verify the current LCD and billing article with your Medicare Administrative Contractor before acting.
Sources: CMS MCD, L40242 MolDX: Genetic Testing for Hereditary Thrombophilia (Noridian); L40238 (Palmetto GBA); L40259 (CGS); L40274 (WPS); CMS MCD, L36155 legacy thrombophilia LCD (Noridian); CMS MCD, L36400 legacy thrombophilia LCD (WPS); Noridian, MolDX LCD consolidation notice, January 22, 2026.