Laboratory Tests - CRD Patients — NCD 181 | CMS Coverage Update

CMS modified NCD 181 governing laboratory test coverage for chronic renal disease (CRD) patients on dialysis, effective March 7, 2026. Here's what billing teams need to know.

The Centers for Medicare & Medicaid Services updated this coverage policy under NCD 181 in its Medicare system. The policy defines which routine and nonroutine lab tests are covered for CRD dialysis patients, at what frequency, and under what medical necessity conditions. No specific CPT or HCPCS codes are listed in the policy document — but the clinical criteria and frequency rules directly drive your charge capture decisions.

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Quick-Reference Table

Field	Detail Copy
Payer	CMS (Centers for Medicare & Medicaid Services)
Policy	Laboratory Tests — CRD Patients
Policy Code	NCD 181
Change Type	Modified
Effective Date	March 7, 2026
Impact Level	High
Specialties Affected	Nephrology, Dialysis Facilities, Independent Labs, End-Stage Renal Disease (ESRD) Programs
Key Action	Audit your lab order frequencies and documentation practices against NCD 181's routine test thresholds before billing claims under this updated policy

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CMS Dialysis Lab Test Coverage Criteria and Medical Necessity Requirements 2026

NCD 181 is the National Coverage Determination governing Medicare coverage of laboratory tests for chronic renal disease patients receiving dialysis. The CMS dialysis lab test coverage policy divides tests into two categories: routine and nonroutine. Knowing the difference is everything for your billing team.

Routine tests are covered at defined frequencies without additional documentation. Nonroutine tests require medical necessity justification tied to diagnosis. If you bill a routine test at a higher frequency than the policy allows, you need to include medical justification in the claim record — or you will face a claim denial.

Here's the structure. Some tests are covered per dialysis session. Others are covered weekly. Others are monthly. And a few fall on a quarterly schedule. CRD dialysis billing hinges on matching your billing frequency to the correct tier.

Per Dialysis Session

CMS covers all hematocrit or hemoglobin tests and clotting time tests furnished incident to dialysis treatments. These are covered every session without additional documentation.

Per Week

Two tests are covered weekly:

#	Covered Indication Copy
1	Prothrombin time — but only for patients on anticoagulant therapy. If your patient is not on anticoagulant therapy, this test is not covered at weekly frequency.
2	Serum creatinine.

Per Week or 13 Per Quarter

BUN (blood urea nitrogen) follows a dual-frequency rule: it's covered once per week or 13 times per quarter. Bill it correctly or expect reimbursement adjustments.

Monthly Routine Tests

The following tests are covered once per month as routine under the CMS CRD lab coverage policy:

Bill any of these more than once per month and you need documented medical justification. Without it, expect a denial.

Quarterly Tests

Two tests sit outside the routine monthly tier:

#	Covered Indication Copy
1	Serum aluminum — covered once every three months
2	Serum ferritin — covered once every three months

These are among the most commonly overbilled tests in the ESRD space. Quarterly means quarterly. One claim per 90-day period, documented clearly.

Hepatitis B Serologic Testing

Hepatitis B testing for CRD dialysis patients follows a separate logic — and this is where billing gets complicated fast.

When a patient first enters a dialysis facility, CMS covers hepatitis B surface antigen (HBsAg) and anti-HBs testing. After that, the frequency of covered testing depends on two variables: vaccination status and serologic status. Get either of those wrong in your documentation and you lose reimbursement.

The coverage policy lays out five distinct patient scenarios. Each scenario triggers a different testing frequency for HBsAg and anti-HBs. CMS is explicit: tests furnished according to this table do not require additional documentation and are paid separately from maintenance dialysis payment bundles.

That last sentence matters. Hepatitis B serologic tests are not bundled into the dialysis composite rate. Bill them separately.

For patients still receiving the hepatitis B vaccine series (not yet complete), treat them as susceptible for screening purposes. Once the third dose is complete, test for anti-HBs one to six months later. A positive response — defined as at least 10 sample ratio units by radioimmunoassay or positive by enzyme immunoassay — means the patient needs only annual anti-HBs testing going forward. If anti-HBs drops below that threshold, a booster dose is indicated and testing resets.

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CMS Dialysis Lab Test Exclusions and Non-Covered Indications

NCD 181 doesn't frame exclusions as a separate list, but the structure of the policy makes the non-covered territory clear.

Any routine test billed at a frequency above the policy thresholds — without documented medical justification — is not covered. This isn't a gray area. CMS is explicit: "Routine tests at greater frequencies must include medical justification."

Any test not on the routine list is considered nonroutine. Nonroutine tests are generally justified by diagnosis code. That means your ICD-10 documentation has to support the clinical rationale for every test that falls outside the routine schedule.

Labs performed by free-standing facilities have an additional requirement: the facility must meet the conditions of coverage for independent laboratories. A claim from a non-compliant lab doesn't become a billing team problem — until it's denied and you're tracking down documentation retroactively.

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Coverage Indications at a Glance

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CMS Dialysis Lab Test Billing Guidelines and Action Items 2026

The real issue with NCD 181 is frequency. Most claim denials in this space come from billing routine tests too often — without documentation to back up the exception. Here's what to do before March 7, 2026.

Copy Action Items

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CPT, HCPCS, and ICD-10 Codes for CRD Dialysis Lab Tests Under NCD 181

Covered CPT Codes (When Selection Criteria Are Met)

NCD 181 as published does not list specific CPT or HCPCS codes. The policy defines covered tests by clinical name and frequency, not by procedure code.

Your billing team should map each test in the policy to the appropriate CPT code using your lab's charge description master and the current AMA CPT code set. The most commonly billed codes in this context include codes for CBC panels, serum electrolytes, creatinine, BUN, hepatitis B surface antigen, and anti-HBs antibody testing — but do not use this list as authoritative. Map directly from your charge master to the clinical test names in the policy.

If you're unsure how specific codes map to NCD 181 coverage criteria, consult your Medicare Administrative Contractor (MAC) for coding guidance specific to your jurisdiction. MAC-level local coverage determinations may provide additional coding specificity beyond what NCD 181 itself contains.

Key Diagnosis Codes

NCD 181 does not specify ICD-10-CM codes. However, claims for these tests should be supported by ESRD and CRD diagnosis codes appropriate to each patient's documented condition. Your compliance officer or billing consultant can help confirm which ICD-10 codes your MAC expects to see supporting nonroutine test claims.

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