TL;DR: The Centers for Medicare & Medicaid Services modified NCD 286 governing islet cell transplantation coverage, effective January 9, 2026. This policy limits Medicare reimbursement strictly to beneficiaries enrolled in NIH-sponsored clinical trials — and if your patient isn't in one, the claim will not pay.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS / Medicare |
| Policy | Islet Cell Transplantation in the Context of a Clinical Trial |
| Policy Code | NCD 286 |
| Change Type | Modified |
| Effective Date | 2026-01-09 |
| Impact Level | High — absolute coverage boundary; no clinical trial enrollment = no coverage |
| Specialties Affected | Transplant surgery, endocrinology, nephrology, inpatient hospital billing |
| Key Action | Before billing any islet cell transplantation claim to Medicare, confirm the patient is actively enrolled in an NIH-sponsored clinical trial and document that enrollment in the medical record |
CMS Islet Cell Transplantation Coverage Criteria and Medical Necessity Requirements 2026
NCD 286 is the National Coverage Determination governing Medicare coverage of islet cell transplantation. The Centers for Medicare & Medicaid Services updated this policy effective January 9, 2026, and the core rule is blunt: Medicare covers islet cell transplantation only when it occurs within the context of an NIH-sponsored clinical trial that includes Medicare beneficiaries.
This isn't a soft guideline. It's a hard coverage boundary. If the transplant happens outside a qualifying trial, CMS considers it noncovered — full stop.
The CMS islet cell transplantation coverage policy applies to patients with Type I diabetes. The procedure involves injecting pancreatic islet cells — the insulin-producing cells of the pancreas — into the portal vein of the recipient. That injection can happen via direct visualization, guided ultrasound, or percutaneous approach. A typical transplant requires over 500,000 islet cells, though that number varies by the recipient's weight.
The desired clinical outcomes are insulin independence, elimination of clinically significant hypoglycemia episodes, and improved glucose control. Your billing team should understand those goals because they frame the medical necessity argument when documentation is reviewed.
What CMS Will Pay For Within a Qualifying Trial
When a Medicare beneficiary is enrolled in a qualifying NIH-sponsored trial, CMS covers a broader set of services than many billing teams expect. The coverage includes:
| # | Covered Indication |
|---|---|
| 1 | The transplantation itself |
| 2 | Acquisition and delivery of the pancreatic islet cells |
| 3 | Clinically necessary inpatient and outpatient medical care |
| 4 | Immunosuppressant drugs |
| 5 | Routine follow-up care for each trial participant |
The statutory basis here is Section 733 of the Medicare Prescription Drug Improvement and Modernization Act of 2003 (P.L. 108-173). That law directed the Secretary of HHS, acting through the National Institute of Diabetes and Digestive and Kidney Disorders, to conduct a clinical investigation of pancreatic islet cell transplantation that includes Medicare beneficiaries.
The definition of "routine costs" under NCD 286 cross-references section 310.1 of the NCD Manual. That section defines routine costs as reasonable and necessary routine patient care costs. Your billing team should pull that definition and keep it in your documentation checklist for any islet transplant claim you submit.
Prior Authorization and Clinical Trial Enrollment
NCD 286 doesn't explicitly require prior authorization in the traditional sense. But the clinical trial enrollment requirement functions as a gatekeeping mechanism that produces the same effect. You cannot submit a covered claim unless the patient is in a qualifying NIH-sponsored trial. That enrollment status needs to be documented before you bill — not reconstructed after a claim denial.
Talk to your compliance officer about how your facility documents and stores clinical trial enrollment verification. If you're billing inpatient hospital services or physician services for islet transplantation, that documentation is your coverage proof. Without it, you have no CMS islet cell transplantation coverage policy to stand on.
CMS Islet Cell Transplantation Exclusions and Non-Covered Indications
The exclusions under NCD 286 are direct. Two categories of services are explicitly noncovered:
1. Islet cell transplantation performed outside a clinical trial. This is the central exclusion. If your patient has Type I diabetes and receives an islet cell transplant at your facility, but is not enrolled in an NIH-sponsored trial, Medicare will not pay. The procedure may be clinically appropriate. It doesn't matter. No trial enrollment, no coverage.
2. Partial pancreatic tissue transplantation. This exclusion holds regardless of clinical trial context. Partial pancreatic tissue transplantation is noncovered under any circumstances within NCD 286.
These two exclusions cover a lot of ground. The real exposure for billing teams is the first one. The second one — partial pancreatic tissue transplantation — is less common in practice, but document your procedure type carefully. If documentation is ambiguous about whether the procedure was a full islet cell transplant or a partial pancreatic tissue procedure, expect a claim denial.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Islet cell transplantation in an NIH-sponsored clinical trial (Type I diabetes) | Covered | No specific codes listed in NCD 286 | Must document active trial enrollment; benefit category: Inpatient Hospital Services and Physicians' Services |
| Immunosuppressant drugs as part of trial participation | Covered | No specific codes listed | Covered under routine costs per NCD Manual section 310.1 |
| Acquisition and delivery of pancreatic islet cells within a trial | Covered | No specific codes listed | Must be clinically necessary and associated with a qualifying trial |
| Routine follow-up care for trial participants | Covered | No specific codes listed | Defined as reasonable and necessary routine patient care costs |
| Islet cell transplantation outside a clinical trial | Not Covered | No specific codes listed | Hard exclusion — no exceptions in NCD 286 |
| Partial pancreatic tissue transplantation | Not Covered | No specific codes listed | Excluded regardless of clinical trial context |
CMS Islet Cell Transplantation Billing Guidelines and Action Items 2026
The effective date is January 9, 2026. Here's what your billing team needs to do.
| # | Action Item |
|---|---|
| 1 | Audit every active islet cell transplantation case on your books before billing. Confirm each patient is enrolled in an NIH-sponsored clinical trial. Pull the trial enrollment documentation and attach it to the medical record. Do this before you drop a claim. |
| 2 | Build a documentation checklist for islet cell transplant claims. That checklist should include: confirmed Type I diabetes diagnosis, NIH trial enrollment verification, procedure approach (direct visualization, guided ultrasound, or percutaneous), cell count and donor pancreas acquisition details, and immunosuppressant regimen. Every item on that list supports medical necessity if CMS audits the claim. |
| 3 | Train your coders on the partial pancreatic tissue exclusion. If your operative notes describe anything resembling partial pancreatic tissue transplantation rather than a full islet cell transplant, flag that case before billing. Islet cell transplantation billing for the wrong procedure type will result in a denied and potentially flagged claim. |
| 4 | Confirm the benefit category you're billing under. NCD 286 covers these services under Inpatient Hospital Services and Physicians' Services. Make sure your charge capture reflects the correct benefit category. Billing under the wrong benefit category is a common source of unnecessary denials on complex transplant cases. |
| 5 | Review your facility's tracking process for NIH-sponsored clinical trials. Your compliance officer and clinical research team should have a current list of active qualifying trials. If that list doesn't exist or isn't shared with the billing team, fix that now. The gap between clinical operations and billing is exactly where coverage errors happen on NCD 286 cases. |
| 6 | Cross-reference section 310.1 of the NCD Manual when coding routine costs. That section defines what qualifies as routine patient care costs under CMS clinical trial coverage policy. Immunosuppressants and follow-up care are included — but you need to document that they're clinically necessary and tied to trial participation, not just incidental to the patient's care. |
| 7 | Flag any ambiguous cases for your compliance officer before January 9, 2026. If you have pending cases where trial enrollment isn't fully documented, or where the procedure type is unclear, don't bill first and ask questions later. The downside risk on a noncovered islet cell transplant claim — especially one that gets flagged in a post-payment audit — is significant. When in doubt, hold the claim and verify. |
| 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 Islet Cell Transplantation Under NCD 286
Covered CPT Codes (When Selection Criteria Are Met)
NCD 286 does not list specific CPT or HCPCS codes. This is a meaningful gap in the policy data, and it creates real islet cell transplantation billing risk.
Without code-level guidance in the NCD itself, your billing team is working from general transplant and inpatient coding conventions. You should contact your Medicare Administrative Contractor (MAC) for guidance on which codes to use when billing islet cell transplantation services under NCD 286. Your MAC can clarify how to code the transplant procedure, the cell acquisition and delivery, immunosuppressant administration, and associated inpatient care.
Don't assume that because the NCD covers the service, the code combination you're using will pass claims editing. MAC-level billing guidelines often fill in the gaps where national policy is silent on codes.
Not Covered / Experimental Codes
NCD 286 does not list specific codes for noncovered services. The noncoverage is defined by clinical scenario — transplantation outside a qualifying trial, and partial pancreatic tissue transplantation — not by code.
This means your claim denial risk on excluded services is driven by documentation review, not code-level edits. A claim for an islet cell transplant that used the right procedure codes but lacked clinical trial documentation will still be denied. The absence of codes in the NCD doesn't make it easier to bill — it means the clinical record carries more weight.
Key ICD-10-CM Diagnosis Codes
NCD 286 does not list specific ICD-10-CM codes. Type I diabetes is the covered patient population, so your diagnosis coding should reflect the patient's Type I diabetes with appropriate specificity. Again, work with your MAC for current guidance on diagnosis coding that aligns with CMS clinical trial coverage policy for islet cell transplantation.
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