CMS modified NCD 149 covering DMSO (dimethyl sulfoxide) for Medicare reimbursement, effective March 7, 2026. Here's what billing teams need to know.
The Centers for Medicare & Medicaid Services updated its coverage policy for dimethyl sulfoxide under National Coverage Determination NCD 149. The policy narrows DMSO reimbursement to a single approved indication — the treatment of interstitial cystitis. Any DMSO claim outside that indication will not be considered reasonable and necessary under Medicare. The policy does not list specific CPT or HCPCS codes, which creates documentation burden your billing team needs to plan for now.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Dimethyl Sulfoxide (DMSO) |
| Policy Code | NCD 149 |
| Change Type | Modified |
| Effective Date | 2026-03-07 |
| Impact Level | Medium |
| Specialties Affected | Urology, Obstetrics & Gynecology, Pain Management, Infusion/Drug Administration |
| Key Action | Confirm every DMSO claim ties directly to an interstitial cystitis diagnosis before submitting — all other indications are non-covered under Medicare |
CMS DMSO Coverage Criteria and Medical Necessity Requirements 2026
The CMS DMSO coverage policy under NCD 149 is straightforward — and strict. Medicare covers DMSO for exactly one indication: the treatment of interstitial cystitis. That's it.
The policy language cites the FDA's own determination as the basis. The FDA has concluded that DMSO is safe and effective for humans only in treating interstitial cystitis. CMS follows that determination directly. If your patient has a different diagnosis, DMSO is not covered, full stop.
Medical necessity for DMSO under NCD 149 requires that the drug be "reasonable and necessary" for the patient's treatment of interstitial cystitis. That phrase — reasonable and necessary — is doing real work here. It means your documentation needs to show active treatment of interstitial cystitis, not just a diagnosis code sitting on the chart. Vague documentation is a direct path to claim denial.
The coverage policy does not mention prior authorization requirements at the national level. However, your Medicare Administrative Contractor may impose additional requirements. Check with your MAC before the effective date of March 7, 2026 if you bill DMSO with any regularity.
One thing this policy does not do is define what "treatment of interstitial cystitis" looks like in practice — frequency, dosage, or setting. That documentation gap puts the burden on your clinical team to make the case. Your medical director should define an internal standard for what goes in the chart before a DMSO claim goes out the door.
CMS DMSO Exclusions and Non-Covered Indications
This is where NCD 149 has real teeth. DMSO has a long history of off-label use — pain management, anti-inflammatory applications, wound care, and as a carrier solvent for other drugs. None of that is covered under Medicare.
The policy is unambiguous: DMSO for any indication other than interstitial cystitis is not considered reasonable and necessary. That language forecloses the argument that a different condition might qualify under some reading of the policy. It doesn't. CMS drew the line at the FDA's guidance, and the FDA drew the line at interstitial cystitis.
If your practice or infusion center bills DMSO for pain management, oncology support, or any other off-label use, those claims will not survive Medicare scrutiny under NCD 149. Reimbursement for those services is not available through Medicare, regardless of how the claim is documented. If you've been billing DMSO for non-interstitial cystitis indications and receiving payment, audit those claims now — and loop in your compliance officer before the March 7, 2026 effective date.
This is the kind of policy where a modest billing error compounds quickly. DMSO treatments can run in series. If even a few claims per month go out with the wrong diagnosis, your exposure adds up fast.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Interstitial cystitis treatment | Covered | No specific codes listed in NCD 149 | Must be documented as reasonable and necessary; check MAC for additional requirements |
| Pain management (off-label) | Not Covered | — | Not FDA-approved for this use; excluded under NCD 149 |
| Anti-inflammatory use (off-label) | Not Covered | — | Falls outside FDA-approved indication; not reasonable and necessary under Medicare |
| Wound care / topical applications (off-label) | Not Covered | — | Not FDA-approved for humans in this context; no Medicare coverage |
| Drug carrier / solvent use (off-label) | Not Covered | — | Outside the sole approved human indication; not covered |
| Any other off-label indication | Not Covered | — | NCD 149 explicitly excludes all non-interstitial cystitis indications |
CMS DMSO Billing Guidelines and Action Items 2026
The absence of specific CPT or HCPCS codes in NCD 149 is the real operational challenge here. It means your billing team can't just run a code audit — you have to audit the diagnosis linkage on every claim.
| # | Action Item |
|---|---|
| 1 | Audit your DMSO claims before March 7, 2026. Pull every claim where DMSO was billed in the last 12 months. Confirm each one ties to an interstitial cystitis diagnosis. Any claim without that link is a potential overpayment. Find them before a MAC audit does. |
| 2 | Establish a diagnosis-first workflow for DMSO orders. Before any DMSO treatment is scheduled, confirm the ordering diagnosis in the chart. Your intake and charge capture process should require an interstitial cystitis diagnosis — documented, not assumed — before DMSO billing proceeds. |
| 3 | Contact your MAC about local requirements. NCD 149 sets the national floor. Your Medicare Administrative Contractor may have a local coverage determination that adds criteria, documentation standards, or prior authorization requirements on top of the national policy. Call or check your MAC's website before the effective date. |
| 4 | Train your coding team on the off-label exclusion. DMSO billing is a small-volume item at most practices, which means it often doesn't get the same attention as high-volume codes. That's where errors hide. Make sure your coders know that any DMSO claim not tied to interstitial cystitis will be denied — and that resubmitting with a different diagnosis won't fix it if the underlying documentation doesn't support it. |
| 5 | Update your charge description master and clinical documentation templates. If DMSO appears in your CDM, add a hard stop or verification flag that requires an interstitial cystitis diagnosis before the charge posts. On the clinical side, make sure your infusion or procedure notes have a field that explicitly documents the interstitial cystitis indication. Sparse notes are a claim denial waiting to happen. |
| 6 | Review any standing orders or recurring treatment plans for DMSO. Interstitial cystitis is often treated with a series of DMSO instillations. If you have patients mid-series, confirm their documentation holds up under the medical necessity standard now — not after an audit. |
| 7 | Loop in your compliance officer if you have any off-label billing history. If your practice has been billing DMSO for non-interstitial cystitis indications — whether intentionally or because of a coding gap — that's a compliance issue, not just a billing issue. Self-disclosure and remediation are far less costly than a post-payment audit finding. Don't wait. |
| 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 DMSO Under NCD 149
Covered CPT and HCPCS Codes
NCD 149 does not list specific CPT or HCPCS codes. CMS has not assigned a designated code set within this policy document. Your billing team should use the appropriate drug administration and drug supply codes based on the clinical setting — outpatient infusion, physician office, or facility — and ensure those codes are paired with a qualifying interstitial cystitis diagnosis. Consult your MAC's billing guidelines for coding direction specific to your region and setting.
Key ICD-10-CM Diagnosis Codes
NCD 149 does not enumerate specific ICD-10-CM codes. However, the covered indication — interstitial cystitis — maps to the N30 category in ICD-10-CM. Your coding team should confirm the appropriate specificity level (chronic interstitial cystitis, other chronic cystitis, etc.) based on the documented clinical presentation. The diagnosis code on the claim must match the treating diagnosis in the medical record. A mismatch between the code and the documentation is a standalone reason for claim denial, independent of the coverage policy itself.
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