Cigna modified MM 0446 for metatarsophalangeal joint replacement of the hallux, effective September 26, 2025. Here's what billing teams need to do.
Cigna Healthcare updated its coverage policy for first MTP joint replacement — the procedure used for severe hallux valgus and hallux rigidus from degenerative joint disease. Under MM 0446 Cigna system, both the procedure code and the implant code land in experimental/investigational territory. The two codes you need to know: CPT 28899 (unlisted procedure, foot or toes) and HCPCS L8699 (prosthetic implant, not otherwise specified). If your practice bills Cigna for this procedure, the effective date of September 26, 2025 means you need to act now.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Cigna Healthcare |
| Policy | Metatarsophalangeal Joint Replacement |
| Policy Code | MM 0446 |
| Change Type | Modified |
| Effective Date | September 26, 2025 |
| Impact Level | High |
| Specialties Affected | Orthopedic Surgery, Podiatry, Foot & Ankle Surgery |
| Key Action | Flag CPT 28899 and HCPCS L8699 as non-covered for Cigna patients before billing; obtain written patient consent for financial liability |
Cigna Metatarsophalangeal Joint Replacement Coverage Criteria and Medical Necessity Requirements 2025
The Cigna metatarsophalangeal joint replacement coverage policy addresses partial or total replacement of the first MTP joint. The clinical context is narrow: persistent, severe, disabling symptoms caused by hallux valgus or hallux rigidus, both stemming from degenerative joint disease of the first MTP joint.
Here's the problem. Cigna does not cover this procedure. Despite a clear clinical indication — a patient with bone-on-bone DJD of the first MTP who has failed conservative treatment — Cigna classifies first MTP joint replacement as experimental and investigational. Medical necessity alone won't get you reimbursement here.
Prior authorization won't save you either. When a payer designates a procedure experimental or investigational, prior authorization is typically unavailable — because the payer won't authorize something it won't cover. Don't burn staff time submitting prior auth requests expecting approval. The medical necessity criteria your physicians document, however solid the clinical record, will not overcome the experimental designation under this coverage policy.
The real issue here is the unlisted code problem. CPT 28899 is an unlisted procedure code, which means there's no defined fee schedule entry for it. Cigna's position effectively ends the conversation before it begins. Your coding team should not submit CPT 28899 with an expectation of payment from Cigna under any circumstances while MM 0446 is in effect.
Cigna MTP Joint Replacement Exclusions and Non-Covered Indications
Cigna explicitly designates both the procedure and the implant as experimental, investigational, and unproven. This isn't a soft exclusion with a pathway around it — both codes are hardcoded into the non-covered category.
CPT 28899, the unlisted foot and toe procedure code most commonly used to bill first MTP joint replacement, carries the experimental/investigational designation. HCPCS L8699, the prosthetic implant code used to separately bill the implant device itself, carries the same designation.
This is a bilateral block. Cigna won't pay for the surgical work, and it won't pay for the implant. If your practice was bundling the implant cost into a facility fee or billing L8699 separately hoping one would go through, both are blocked under this policy.
The designation applies regardless of the surgical approach, the specific implant manufacturer, or the severity of the patient's condition. Cigna's position is that the evidence base for first MTP joint replacement is insufficient to support coverage. That may feel frustrating when you have a patient with severe hallux rigidus who has exhausted every conservative option. But the policy is what it is — and billing for it anyway creates a claim denial problem and a compliance risk.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Partial or total first MTP joint replacement for hallux valgus with degenerative joint disease | Not Covered — Experimental/Investigational | CPT 28899, HCPCS L8699 | Both procedure and implant codes are designated experimental; no coverage pathway |
| Partial or total first MTP joint replacement for hallux rigidus with degenerative joint disease | Not Covered — Experimental/Investigational | CPT 28899, HCPCS L8699 | Same blanket exclusion applies regardless of severity or failed conservative treatment history |
Cigna Metatarsophalangeal Joint Replacement Billing Guidelines and Action Items 2025
The metatarsophalangeal joint replacement billing picture under Cigna MM 0446 is straightforward — and that's not a compliment. Here's what your team should do right now.
| # | Action Item |
|---|---|
| 1 | Flag CPT 28899 and HCPCS L8699 in your charge capture system as non-covered for Cigna patients. Do this before September 26, 2025 if you haven't already. Any claim submitted after the effective date runs directly into a denial wall with no medical necessity appeal pathway. |
| 2 | Issue Advance Beneficiary Notice equivalents for Cigna commercial patients. Cigna isn't Medicare, so it's not literally an ABN — but the concept applies. Patients scheduled for first MTP joint replacement need written notice that Cigna will not cover the procedure or the implant. Get that signed before surgery. If you don't, you may be stuck absorbing the cost. |
| 3 | Pull your accounts receivable for any pending Cigna claims with CPT 28899 or HCPCS L8699. If you have claims in flight from before the September 26 effective date, check what policy version applied at the time of service. If the procedure was already experimental under a prior version of MM 0446, those claims have the same problem. |
| 4 | Educate your scheduling and pre-authorization staff. They need to stop routing first MTP joint replacement cases through the standard Cigna prior auth workflow. There's no auth to get. The right workflow is a financial clearance conversation with the patient before the case gets booked. |
| 5 | Document alternative procedures in the medical record when applicable. Cigna does cover MTP joint fusion (arthrodesis) for hallux rigidus. If your surgeon performs a fusion instead of a replacement, the billing picture is completely different. Make sure your operative report clearly reflects what was done — fusion vs. replacement — so the right code gets assigned. |
| 6 | Talk to your compliance officer if you're billing a mixed payer population. If your practice sees both Cigna and non-Cigna patients for first MTP joint replacement, you need a clear protocol. Other commercial payers may cover this procedure. Your billing guidelines need to differentiate by payer, not just by procedure. If you're unsure how to structure that workflow, loop in your billing consultant before the effective date. |
| 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 Metatarsophalangeal Joint Replacement Under MM 0446
The Cigna MM 0446 policy lists two codes. Both are designated experimental and investigational. There are no covered codes in this policy — the entire procedure falls outside coverage.
Not Covered / Experimental Codes
| Code | Type | Description | Reason |
|---|---|---|---|
| 28899 | CPT | Unlisted procedure, foot or toes | Considered Experimental/Investigational/Unproven when used for MTP joint replacement |
| L8699 | HCPCS | Prosthetic implant, not otherwise specified | Considered Experimental/Investigational/Unproven when used for MTP joint replacement |
The policy does not list specific ICD-10-CM diagnosis codes. No covered CPT codes exist under this policy.
One thing worth flagging for your coding team: CPT 28899 is an unlisted code that requires a cover letter and operative report with every submission. Even if you were attempting to bill Cigna and argue for reimbursement on appeal, the unlisted code documentation burden is high. The experimental designation makes that effort a poor use of time and resources. Direct your coding team's energy toward the patient financial liability documentation instead.
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