MolDX Delays Its DCIS Biomarker Testing Coverage Decision
Short answer: In mid-2026, MolDX indefinitely postponed finalizing its proposed non-coverage LCD for DCIS radiation-decision biomarker tests, including PreludeDx's DCISion-RT. The draft, open for comment since July 2025, would have limited coverage to tests proving a "sufficiently low-risk" patient group with no more than a 5% absolute recurrence-risk reduction from radiation. The delay leaves Medicare billing for these tests unresolved, not approved.
What Just Happened
In July 2025, Palmetto GBA — acting as one of MolDX's Medicare Administrative Contractors — posted a draft local coverage determination (LCD) titled "MolDX: Biomarker Testing for Risk Stratification in DCIS." As written, the policy proposes non-coverage for biomarker tests used to help ductal carcinoma in situ (DCIS) patients and their radiation oncologists decide whether adjuvant radiation therapy can safely be skipped after breast-conserving surgery. The comment period ran through August 31, 2025, and the draft carries the CMS database's usual "N/A" effective-date marker for a policy still under review.
According to reporting from health-policy analyst Bruce Quinn at Discoveries in Health Policy, MolDX has now pushed that finalization back indefinitely, stating only that "additional information will be forthcoming in the following months." That is a meaningfully different outcome than either finalizing the non-coverage policy as drafted or withdrawing it. For labs running DCIS radiation-decision biomarker tests — most visibly PreludeDx's DCISion-RT, a 7-gene biosignature paired with clinicopathologic features — the practical result is an extended stretch of coverage uncertainty rather than a resolved answer in either direction.
The Coverage Bar in the Draft: What "Sufficiently Low-Risk" Actually Requires
The draft LCD does not propose blanket non-coverage forever — it sets out a path back to coverage that is worth reading closely, because it doubles as a preview of what MolDX will expect from any biomarker test in this space going forward. On the patient side, the draft requires: a DCIS diagnosis without concurrent invasive carcinoma; no plan for mastectomy; no prior breast radiation; a treatment plan that already includes radiation therapy, with the physician and patient willing to forgo it if the test classifies the patient as low-risk; and no prior similar biomarker testing for the same episode of care. On the test side, the assay must have completed MolDX's Technical Assessment, and it must either show a "significant improvement in accuracy" over existing clinical-pathologic tools or perform at least as well as a biomarker test MolDX already covers.
The load-bearing definition, though, is what counts as "sufficiently low-risk": a patient subgroup with no more than a 5% absolute reduction in ipsilateral breast tumor recurrence from adding radiation to surgery, compared with surgery alone. That is a considerably tighter bar than clinicians are used to from existing tools like the MSKCC DCIS nomogram or the Van Nuys Prognostic Index, which stratify risk but were not designed, in MolDX's assessment, with this specific absolute-risk-reduction threshold in mind. The draft's stated rationale for proposing non-coverage in the first place was that current biomarker tests haven't been directly compared against those existing systems, and haven't demonstrated superiority over them under that framework.
Why MolDX Postponed Finalizing It
The delay did not happen in a vacuum. Per Quinn's reporting, PreludeDx pushed back publicly on the draft, pointing to more than a decade of clinical use of DCISion-RT and over ten published studies supporting it, along with backing from breast cancer specialists. The same reporting cites PREDICT registry data showing DCISion-RT changed the radiation-therapy recommendation for roughly 42% of patients tested, with a net reduction in over-treatment — a real-world utilization argument, not just an analytic-validity one.
MolDX's counter-framing, according to that same reporting, is that this kind of evidence amounts to "rhetorical proof": years of use and specialist endorsement offered in place of the head-to-head comparative validation the draft LCD's framework asks for. That tension — longstanding clinical adoption and real-world practice-changing data on one side, a stricter comparative-evidence bar on the other — is exactly what MolDX now says it needs more time to work through before finalizing anything. Until it does, the draft's proposed non-coverage language is neither in effect nor withdrawn.
This Fits a Pattern in MolDX's 2026 Evidence Bar
The DCIS delay sits alongside a busy stretch of MolDX oncology policymaking. In the same late-August 2026 review cycle, MolDX posted three related draft LCDs covering NGS testing for hematologic malignancies, genome-wide structural-variant detection methods, and transcriptional biomarkers for renal cell carcinoma — landing on positive, limited, and non-covered outcomes respectively; we cover that batch in detail in our look at MolDX's proposed NGS coverage framework for blood cancers. Read together with the DCIS delay, the throughline is consistent: MolDX will extend coverage where a test's intended-use population is tightly defined and its incremental value over existing tools is demonstrated head-to-head, and it will hold the line — through denial, tight scope limits, or simply not finalizing — wherever that direct comparison is missing, however long a test has been in clinical use. We've seen the same evidentiary posture outside oncology in MolDX's biomarker coverage policy for MASLD/MASH liver disease risk stratification, and it lines up with the broader direction described in our coverage of MolDX's proposed national program expansion.
What Labs, Clinicians, and RCM Teams Should Do Now
For labs currently billing Medicare for DCIS radiation-decision biomarker testing, treat the indefinite delay as an open question, not a green light. Absent a final, effective LCD, claims may still be evaluated under existing article guidance or case-by-case medical necessity review; an Advance Beneficiary Notice (ABN) conversation with the patient remains the safer operational default until MolDX publishes the "additional information" it has promised. Ordering clinicians should document, on every order, why the test result is expected to change the radiation-therapy decision for that specific patient — that documentation trail matters regardless of which way this LCD eventually resolves. RCM teams should flag these claims for manual review rather than routine auto-adjudication assumptions, and should build workflows now for either a covered or non-covered final outcome, since the draft language could still finalize largely as written once MolDX completes its review. For the broader operational picture on why advanced genetic and genomic testing claims get denied in the first place, see our guide to genetic testing denials.
Frequently Asked Questions
Is DCISion-RT covered by Medicare right now?
There is no final LCD either covering or denying it. MolDX indefinitely postponed finalizing the proposed non-coverage policy in 2026, so billing outcomes for DCIS radiation-decision biomarker tests remain unresolved in the affected Palmetto GBA jurisdictions. Labs should not assume automatic coverage and should discuss ABNs with ordering clinicians and patients where appropriate.
What does "sufficiently low-risk" mean in the draft LCD?
The draft defines it as a patient subgroup with no more than a 5% absolute reduction in ipsilateral breast tumor recurrence from adding radiation therapy to surgery, compared with surgery alone — a specific, comparative threshold rather than a general risk category.
Why did MolDX delay the decision instead of finalizing or withdrawing it?
According to reporting on the delay, MolDX indicated it needs more time to work through the evidence, following pushback from PreludeDx and clinicians citing over a decade of DCISion-RT's clinical use and real-world data showing the test changed radiation-therapy recommendations for about 42% of patients tested. MolDX has said additional guidance is coming in the following months but has not committed to a date.
Does this affect all DCIS biomarker tests, or just DCISion-RT?
The draft LCD is written around the test category — biomarker testing for risk stratification in DCIS — not one product by name, so any test in that category would be evaluated against the same proposed criteria once finalized.
What should a lab do while this LCD remains unfinalized?
Document medical necessity and the intended clinical use precisely on every order, prepare ABN workflows for Medicare patients, monitor the CMS Medicare Coverage Database for a status change, and avoid assuming the draft's proposed criteria will finalize unchanged.
This article is educational information for laboratory, revenue cycle, and clinical professionals. It is not medical advice, legal advice, coding advice, or a guarantee of payment. Coverage policies are proposals until finalized, and criteria or effective dates can change during MolDX's review — always verify current status against the CMS Medicare Coverage Database and your MAC's published guidance before submitting claims or making clinical decisions. ScreenMyGene does not determine coverage for any individual claim. Learn more about our work at ScreenMyGene.
Sources: CMS Medicare Coverage Database, proposed LCD "MolDX: Biomarker Testing for Risk Stratification in DCIS" (Palmetto GBA), comment period July 17–August 31, 2025; Quinn B., "MolDX MACs Delay Finalization of Prelude DCISion-RT LCD," Discoveries in Health Policy, September 2026; Quinn B., "MolDx Issues Bonanza of New LCDs in Late August 2026," Discoveries in Health Policy, September 2026.