Summary: The Centers for Medicare & Medicaid Services modified its glycated hemoglobin/glycated protein coverage policy, effective May 15, 2026. Here's what billing teams need to do.
CMS updated its policy governing glycated hemoglobin (HbA1c) and glycated protein testing—two of the most frequently billed lab services in primary care, endocrinology, and diabetes management programs. This policy change carries real financial exposure for any practice billing Medicare for routine or diagnostic glucose monitoring labs. The policy does not list specific CPT, HCPCS, or ICD-10 codes in the available document—read the full notice on the CMS source before assuming your existing charge capture is compliant.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Glycated Hemoglobin/Glycated Protein |
| Policy Code | N/A |
| Change Type | Modified |
| Effective Date | May 15, 2026 |
| Impact Level | High |
| Specialties Affected | Primary care, endocrinology, internal medicine, nephrology, clinical laboratory, diabetes education programs |
| Key Action | Review your glycated hemoglobin billing workflows and medical necessity documentation before May 15, 2026 |
CMS Glycated Hemoglobin Coverage Criteria and Medical Necessity Requirements 2026
The CMS glycated hemoglobin/glycated protein coverage policy governs when Medicare will reimburse for HbA1c testing and related glycated protein assays. This is not a niche policy. HbA1c testing is one of the highest-volume lab services billed to Medicare, and any modification to medical necessity criteria ripples across thousands of practices.
Because the policy document available does not include the full modified criteria text, you should pull the source directly at the CMS policy URL before May 15, 2026. Do not rely on your current workflows as a proxy for what the updated policy requires—modified coverage policies often shift frequency limits, qualifying diagnoses, or documentation thresholds in ways that aren't obvious until a claim denial shows up.
What we know from the policy title and CMS's historical framework: glycated hemoglobin (HbA1c) testing typically requires a documented diagnosis of diabetes mellitus or a clinical indication supporting diabetes monitoring or screening. Glycated protein testing—including fructosamine assays—has historically been covered under narrower circumstances, often when HbA1c is unreliable due to hemolytic anemia, abnormal hemoglobin variants, or other conditions affecting red blood cell turnover.
The real issue with a "modified" designation on this policy is frequency. CMS has historically allowed HbA1c testing up to twice per year for stable diabetic patients and more frequently when management changes are being made. If this modification tightens those frequency parameters, or changes the diagnosis codes required to support medical necessity, your billing team needs to know before the effective date—not after the first round of denials.
Prior authorization is not typically required for routine HbA1c testing under Medicare Part B. But prior authorization requirements can shift when coverage policy criteria change. Confirm whether this modification introduces any new prior auth requirements for less common glycated protein assays.
CMS Glycated Hemoglobin/Glycated Protein Exclusions and Non-Covered Indications
CMS has historically treated certain glycated protein testing as non-covered when the clinical indication doesn't meet medical necessity thresholds. Routine screening in patients without a diabetes diagnosis or documented risk factors is the clearest example.
Fructosamine and other glycated protein assays have faced stricter scrutiny than HbA1c under Medicare. They've historically been considered non-covered when ordered simply as an alternative to HbA1c in patients without a clinical reason to avoid HbA1c testing. If a patient can receive standard HbA1c testing, ordering a glycated protein assay instead doesn't automatically establish medical necessity.
Testing frequency beyond covered limits is another common exclusion trigger. If the modification establishes new limits—quarterly caps, annual maximums, or diagnosis-specific frequency rules—claims that exceed those limits will deny regardless of the clinical rationale in the chart.
The full scope of exclusions under the modified policy is not available in the current document. Pull the updated policy text from the CMS source before billing against assumptions.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| HbA1c monitoring for diagnosed diabetes mellitus | Covered (historical CMS standard) | Not listed in available policy data | Medical necessity documentation required |
| HbA1c testing for suspected diabetes / pre-diabetes assessment | Covered under qualifying conditions (historical) | Not listed in available policy data | Verify qualifying diagnosis criteria in updated policy |
| Glycated protein (fructosamine) when HbA1c is clinically unreliable | Covered under narrow criteria (historical) | Not listed in available policy data | Requires documentation of clinical reason HbA1c is not appropriate |
| Routine glycated protein testing as substitute for HbA1c without clinical indication | Not Covered (historical CMS position) | Not listed in available policy data | Claim denial risk without documented medical necessity |
| Testing frequency exceeding covered limits | Not Covered | Not listed in available policy data | Confirm updated frequency rules before May 15, 2026 |
Note: This table reflects CMS's historical coverage framework for glycated hemoglobin and glycated protein. The specific criteria in the modified policy are not available in the source document provided. Verify all indications against the updated policy text before the effective date.
CMS Glycated Hemoglobin Billing Guidelines and Action Items 2026
This is where the work happens. You have until May 15, 2026 to get your billing workflows aligned with the modified policy. Here's what to do now.
| # | Action Item |
|---|---|
| 1 | Pull the full modified policy text directly from CMS before May 15, 2026. The source document at the CMS policy page is the authoritative version. Read the actual modified criteria—don't work from a summary or assume continuity with your current workflows. |
| 2 | Audit your current HbA1c and glycated protein billing guidelines against the modified policy. Look specifically at frequency limits, qualifying diagnosis requirements, and any changes to how CMS defines medical necessity for glycated protein assays versus standard HbA1c. |
| 3 | Update your charge capture and order entry workflows to reflect any new frequency or diagnosis requirements. If the modification changes how often these tests can be billed, your EHR order sets and billing rules need to reflect that before the effective date—not after you start collecting denials. |
| 4 | Review your medical necessity documentation templates. If providers aren't documenting the clinical rationale for glycated protein testing at the time of order, start now. Retrofitting documentation after a claim denial is harder and creates audit exposure. |
| 5 | Check for any changes to prior authorization requirements. Routine HbA1c testing under Medicare Part B has not historically required prior auth, but modified coverage policies can introduce new requirements. Verify this is still the case under the updated policy. |
| 6 | Brief your clinical and lab teams on the modified criteria. Glycated hemoglobin billing failures often originate at the order level—a provider ordering a test that no longer meets medical necessity under the updated policy. Get the updated requirements in front of ordering providers, not just your billing team. |
| 7 | If your practice uses a MAC-level local coverage determination (LCD) for glycated testing, check for MAC updates. A CMS national policy modification often prompts Medicare Administrative Contractor updates to companion LCDs. Your MAC may issue supplemental guidance before or after May 15, 2026 that adds specificity to the national policy change. |
If you're running high volume on glycated protein assays—nephrology practices and labs serving patients with hemolytic conditions especially—talk to your compliance officer before the effective date. The financial exposure on a coverage policy modification at this scale is real, and retroactive claim corrections are painful.
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
CPT, HCPCS, and ICD-10 Codes for Glycated Hemoglobin/Glycated Protein Under This Policy
The policy document available for this modification does not list specific CPT, HCPCS, or ICD-10 codes. Do not invent or assume codes based on this post.
What to Do Instead
Pull the current CMS policy source directly to identify every code listed under the modified policy. Common codes historically associated with glycated hemoglobin and glycated protein testing include HbA1c assays and fructosamine assays, but the specific codes covered, excluded, or newly affected by this modification must come from the official CMS document.
Do not build or update a charge capture list from memory or prior policy versions. Modified CMS coverage policies frequently add, remove, or reclassify codes. Your billing team needs the code list from the actual updated policy, not from the previous version.
Once you have the updated code list from CMS, cross-reference it against your current charge master and EHR order catalog. Any code that appears in the modified policy but not in your current setup is a gap. Any code your team currently bills that no longer appears in the covered list is a denial risk starting May 15, 2026.
Get the Full Picture
Track this policy across versions, search 1,500+ policies by CPT code, and get real-time alerts when any payer changes coverage.