What is a National Coverage Determination (NCD)?

How an NCD works

Section 1862(l) of the Social Security Act defines a National Coverage Determination as a determination by the Secretary of Health and Human Services about whether a particular item or service is covered nationally under Medicare. In practice the decision answers the reasonable-and-necessary question of section 1862(a)(1)(A) once for the whole country: the NCD states the covered indications, the conditions a patient must meet, the limitations that apply, and sometimes the evidence CMS wants collected under coverage with evidence development. Where an NCD is silent, coverage is decided locally by each contractor through Local Coverage Determinations or claim-by-claim review; where an NCD speaks, the contractor applies it as written. The determinations are collected in the Medicare National Coverage Determinations Manual, Publication 100-03, and every claim-processing system edit that enforces one traces back to a manual section and the change request that put it there.

NCDs are numbered by manual chapter and section. The first component is the chapter, which groups policies by clinical area or benefit category, and the remaining components identify the policy and any sub-policy; 190.23 is the twenty-third policy in the laboratory chapter and 20.4 is the fourth in the cardiovascular chapter. The number does not change when the policy is revised, so a billing system can key its edits to the NCD number and read the effective date of the current version separately. Each policy page here shows that version date, the implementation date for contractors and the transmittal that carried the change.

How CMS issues or changes an NCD

A new or revised determination goes through the National Coverage Analysis process. CMS opens the analysis in response to a formal request from a manufacturer, a professional society, a beneficiary or a contractor, or on its own initiative, and posts a tracking sheet in the Medicare Coverage Database that starts a 30-day public comment period. Within six months of the opening, or nine months when CMS commissions an external technology assessment or convenes the Medicare Evidence Development and Coverage Advisory Committee, the agency publishes a proposed decision memorandum and takes a second 30-day comment period. The final decision follows within 60 days of the proposed one and is implemented through a manual change request that tells contractors the effective date and the claims edits to install. Reconsideration follows the same path, and the decision memoranda remain in the database as the written record of why CMS covered, limited or declined to cover the service.

The NCD list by manual chapter

Most searched NCDs

The laboratory NCDs and their ICD-10 edit lists

Twenty-three NCDs in chapter 190 came out of the negotiated rulemaking on clinical laboratory services that produced the 2001 final rule, and they are different from every other policy in the manual: each one carries a national list of ICD-10-CM diagnosis codes that support medical necessity and a list that does not. CMS publishes those lists as a quarterly spreadsheet, contractors load them as automated edits, and a laboratory claim for one of the tests pays only when the line carries a covered diagnosis. The 23 laboratory NCD pages on this site show the procedure codes each policy edits, the covered and non-covered code counts with samples, and the current policy text, which is the quickest way to see why a urine culture, a lipid panel or a prothrombin time denied. Start from the coverage hub, where the laboratory policies are listed first.

What an NCD denial looks like, and what to do

When a contractor denies a service under an NCD the electronic remittance carries claim adjustment reason code claim adjustment reason code 50, non-covered because not deemed a medical necessity, with remark code remark code N386, which states that the decision was based on a National Coverage Determination. The remark names the policy, so the first step is to open the NCD page, compare the documented indication with the covered indications, and confirm the diagnosis on the claim is one the policy accepts. If the service was furnished outside the NCD's conditions the denial is correct and the beneficiary is liable only when a valid Advance Beneficiary Notice was obtained before the service; if the record supports a covered indication that the claim did not communicate, a corrected claim or a redetermination within 120 days with the documentation attached is the route. Appeals cannot challenge the NCD itself; only the reconsideration process described above can change the policy.

Related coverage reference

Frequently asked questions

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.

• Medicare Coverage Database NCDs via the CMS Coverage API
  Version API snapshot 2026-09-27 · effective 2026-09-20 · file national-coverage-ncd.jsonSHA-256 a90fadfd264b9ef4…
• Laboratory NCD ICD-10 code lists, January 2026
  Version January 2026 · effective 2026-01-01 · file 2026100-Initial-ICD10-NCD-Spreadsheet-20250721-508.xlsxSHA-256 57ff5cd37ba523d3…