Glycated Hemoglobin/Glycated Protein — NCD 100 | CMS Coverage Update

TL;DR: The Centers for Medicare & Medicaid Services modified NCD 100, its glycated hemoglobin/glycated protein coverage policy, effective March 7, 2026. Here's what changes for billing teams.

This update to NCD 100 in the CMS Medicare system affects how often you can bill glycated hemoglobin and glycated protein tests for diabetic patients — including tighter frequency limits for controlled patients, specific exceptions for pregnant women, and documentation requirements when testing exceeds four times per year. The policy does not list specific CPT or HCPCS codes. Your team will need to map your charge capture to the clinical criteria spelled out in the updated national coverage determination.

Quick-Reference Table

CMS Glycated Hemoglobin Coverage Criteria and Medical Necessity Requirements 2026

The CMS glycated hemoglobin/glycated protein coverage policy covers these tests as medically necessary for managing and controlling diabetes. CMS also recognizes medical necessity for assessing hyperglycemia, a history of hyperglycemia, and dangerous hypoglycemia.

The real issue here is frequency. CMS draws a hard line: for controlled diabetic patients, glycated hemoglobin testing is covered no more than once every three months. That's four times per year, max — unless you have documentation that justifies more.

When More Frequent Testing Is Covered

CMS allows testing every one to two months when a patient's diabetes regimen has changed to improve control. It's also allowed when intercurrent events — major surgery, glucocorticoid therapy — have disrupted a previously stable patient. In those cases, you need documentation that shows why the standard quarterly schedule wasn't appropriate.

For diabetic pregnant women, glycated protein (fructosamine) testing is covered monthly. That's a specific carve-out, and it applies to glycated protein — not glycated hemoglobin. The clinical reason is that glycated protein measures glycemic control over one to two weeks, making it the better tool for the rapid metabolic shifts of pregnancy.

Testing Beyond Four Times Per Year

Testing more than four times per year for uncontrolled type 1 or type 2 diabetes can be covered. But "uncontrolled" isn't self-evident on a claim. Your documentation must show the clinical basis for that frequency. CMS is explicit: medical necessity documentation must support any testing that exceeds the standard guidelines. Without it, you're looking at a claim denial.

Glycated Protein as an Alternative

Glycated protein — also called fructosamine — is covered as an alternative to glycated hemoglobin in specific situations. If a patient has hemolytic anemia or a hemoglobinopathy, standard glycated hemoglobin assays may produce unreliable results due to interference from elevated fetal hemoglobin or variant hemoglobin molecules. In those cases, glycated protein is the appropriate test and is covered.

When a glycated hemoglobin assay is run first and the lab identifies a possible analytical interference, the lab should inform the ordering physician. At that point, switching to glycated protein testing is clinically and coverage-justified.

CMS Glycated Hemoglobin Exclusions and Non-Covered Indications

CMS does not cover glycated hemoglobin testing more than once every three months for a controlled diabetic patient when the sole purpose is confirming stable metabolic control. There's no medical necessity basis for that frequency when the patient is on target.

Monthly glycated hemoglobin or glycated protein testing is not covered for the general diabetic population. The monthly frequency applies only to diabetic pregnant women, and only for glycated protein.

Testing without documentation to support medical necessity — especially when frequency exceeds four times per year — is not considered reasonable and necessary. If you can't show in the medical record why the patient needed more frequent testing, the reimbursement risk falls on your practice.

Coverage Indications at a Glance

CMS Glycated Hemoglobin Billing Guidelines and Action Items 2026

CPT, HCPCS, and ICD-10 Codes for Glycated Hemoglobin/Glycated Protein Under NCD 100

A Note on Codes

NCD 100 does not specify any CPT, HCPCS, or ICD-10 codes. Code mapping for this policy must come from your applicable Medicare Administrative Contractor's local coverage determination or billing guidelines — not from the national policy itself.

Do not assign codes to this NCD without MAC validation. A mismatched code-to-policy mapping is a fast path to a claim denial — and potentially a reopened claim audit if the pattern repeats.

Check your MAC's LCD for the definitive code list that aligns with this coverage policy. If you're unsure which MAC jurisdiction applies to your practice, CMS publishes the full MAC contractor map at cms.gov.