CMS Diagnostic Pap Smears NCD 351 Retired: What Billing Teams Need to Know in 2026

CMS has formally retired NCD 351 — the National Coverage Determination governing diagnostic Pap smears — with an effective date of March 12, 2026. This policy modification redirects coverage guidance to NCD §190.2, consolidating the rules under a single cross-referenced policy rather than maintaining a standalone NCD. If your practice bills Medicare for diagnostic Pap smear services, this structural change has direct implications for how you locate and apply medical necessity criteria going forward.

What CMS NCD 351 Retirement Means for Medicare Billing

The Centers for Medicare & Medicaid Services originally maintained NCD 351 as a dedicated policy under the Diagnostic Laboratory Tests benefit category, covering indications and limitations for diagnostic Pap smears billed to Medicare. As of the retirement effective date, that standalone NCD no longer functions as the operative guidance document.

Instead, CMS has directed all applicable coverage logic to NCD §190.2, which governs laboratory services more broadly. The retirement was formally issued March 9, 2023, with an effective and implementation date of April 10, 2023 — but billing teams working from cached or static references may still be pointing to NCD 351 as an active policy. The March 2026 policy key update (351-v2) is the version confirming this retired status in the Medicare Coverage Database.

This is a consolidation move by CMS, not a coverage elimination. Diagnostic Pap smear services are not suddenly non-covered — the rules have moved addresses.

Understanding the Cross-Reference to NCD §190.2

CMS policy retirements that include a cross-reference are functionally redirects. NCD §190.2 is the controlling document your billing team should now consult when determining whether a diagnostic Pap smear meets Medicare medical necessity criteria for coverage.

The practical implication: any coverage determination workflows, payer policy cheat sheets, or denial appeal templates your team built around NCD 351 should now point to NCD §190.2 on the CMS Medicare Coverage Database. Failing to make this update creates real risk — particularly if your team is citing a retired NCD on appeal letters or in prior authorization requests, which can undermine the credibility of a medical necessity argument.

It's also worth noting that NCD 351 falls squarely under the Diagnostic Laboratory Tests benefit category. If your organization has benefit category mapping in your billing system, verify that this service line remains correctly mapped even after the retirement.

Affected Codes

The policy data published for NCD 351-v2 does not list specific CPT, HCPCS, or ICD-10-CM codes. This is consistent with a retirement/redirect policy — the applicable codes are now addressed under the cross-referenced NCD §190.2 rather than repeated in the retired NCD.

What this means for your team: Do not assume that the absence of codes in NCD 351-v2 means no codes apply to diagnostic Pap smear billing. Pull the current code tables directly from NCD §190.2 in the CMS Medicare Coverage Database to identify the operative CPT and HCPCS codes under active coverage guidance.

If your billing system auto-populates NCD references by code, confirm those mappings have been updated to point to §190.2 rather than the retired 351.

Diagnostic Pap Smears vs. Screening Pap Smears: A Billing Distinction That Matters

Before updating your workflows, it's worth clarifying a distinction that trips up billing teams regularly. Diagnostic Pap smears — the service covered under NCD 351 and now §190.2 — are ordered in response to signs, symptoms, or clinical findings. They are billed as diagnostic laboratory services and evaluated under diagnostic coverage rules.

Screening Pap smears for Medicare are a separate benefit, governed by different frequency and eligibility rules entirely. Confusing the two categories is one of the most common sources of denials in gynecologic lab billing. If your team has been using NCD 351 to support both diagnostic and screening claims, that's a compliance gap worth addressing now.

The retirement of NCD 351 is a good forcing function to audit how your practice distinguishes and documents these two service types in the medical record.

Prior Authorization and Medical Necessity Documentation

NCD 351-v2 does not reference prior authorization requirements — this is consistent with most diagnostic laboratory NCDs, which rely on medical necessity documentation rather than pre-service authorization. However, the retirement and redirect to §190.2 means your team should verify whether §190.2 includes any additional documentation requirements that weren't explicitly called out in the old NCD 351.

For diagnostic Pap smears, the clinical record should clearly support:

Absent that documentation, claims are vulnerable to medical necessity denials regardless of which NCD is operative.

What Your Billing Team Should Do