TL;DR: Aetna, a CVS Health company, modified CPB 0669 for subtalar implants, effective October 8, 2025. Every indication and every named device is classified as experimental, investigational, or unproven — meaning clean reimbursement on these procedures through Aetna is not happening.
Aetna's subtalar implant coverage policy under CPB 0669 in the Aetna system draws a hard line: no subtalar implant procedure qualifies as medically necessary for any listed indication. The policy names 31 specific devices and covers the primary billing codes — Category III CPT codes 0335T, 0510T, and 0511T for sinus tarsi implant insertion, removal, and removal/reinsertion, along with HCPCS S2117 for arthroereisis — all classified as non-covered. If your practice performs these procedures and bills Aetna, read this before October 8, 2025.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | Aetna, a CVS Health company |
| Policy | Subtalar Implant for Foot Deformity |
| Policy Code | CPB 0669 |
| Change Type | Modified |
| Effective Date | October 8, 2025 |
| Impact Level | High |
| Specialties Affected | Podiatry, Orthopedic Surgery, Foot & Ankle Surgery |
| Key Action | Audit any open Aetna claims or prior authorization requests for CPT 0335T, 0510T–0511T, and HCPCS S2117 before October 8, 2025 |
Aetna Subtalar Implant Coverage Criteria and Medical Necessity Requirements 2025
The short version: there are no coverage criteria for subtalar implants under this policy. Aetna's position is that the effectiveness of these procedures has not been established. That means there is no clinical pathway — no documentation checklist, no prior authorization approval process — that gets a subtalar implant claim paid.
This is a blanket experimental designation. It applies to every indication listed in the policy and every named device. Aetna CPB 0669 does not distinguish between pediatric and adult patients, congenital versus acquired deformity, or first-line versus salvage use. If the procedure involves a subtalar implant, Aetna will not cover it.
For billing teams, this has a specific consequence: prior authorization requests for these procedures will be denied. Don't spend time building a medical necessity argument for CPT 0335T or HCPCS S2117 with an Aetna plan. The denial will come from the coverage policy itself, not from missing documentation.
This also means reimbursement through standard Aetna commercial plans is off the table for the codes tied to this policy. If a provider wants to perform these procedures, they need a financial arrangement with the patient before the service is rendered — a written notice of non-coverage and an Advance Beneficiary Notice equivalent at minimum. Talk to your compliance officer about what Aetna-specific patient disclosure requirements look like in your state.
Aetna Subtalar Implant Exclusions and Non-Covered Indications
Aetna's experimental designation covers five named indications. None of them are edge cases. These are common diagnoses that foot and ankle specialists treat regularly.
Subtalar instability (ICD-10 M24.871–M24.876, M25.271–M25.279, M25.371–M25.376) is explicitly listed. So is talipes equinovarus (clubfoot) — both congenital (Q66.0–Q66.2) and acquired (M21.541–M21.549). Foot drop (M21.071–M21.079, M21.371–M21.379, M21.6x1–M21.6x9) makes the list. And the broadest category — flatfoot deformity, covering pes planus, pes planovalgus, pes valgus, and posterior tibial tendon dysfunction — is excluded across both congenital (Q66.50–Q66.52) and acquired (M21.40–M21.42) presentations.
The policy also includes a catchall: "any other conditions." That language closes off any argument that an unlisted indication might slip through.
The device list is equally specific. Thirty-one named implants appear in the policy. The list spans every major brand in the arthroereisis market — HyProCure, MBA, ProStop, bioBLOCK, OsteoSpring FootJack, and many others. If your surgeon uses a device that isn't on this list, Aetna's "not an all-inclusive list" language still applies. Don't assume an unlisted device creates a billing opportunity.
Two CPT codes appear as "other CPT codes related to the CPB" — CPT 28735 (arthrodesis, midtarsal or tarsometatarsal, with osteotomy) and CPT 29907 (arthroscopy, subtalar joint, surgical with subtalar arthrodesis). These aren't experimental in the same way — they represent adjacent procedures that may come up in the same clinical context. The policy associates them without giving them a clean covered/not-covered designation. If you're billing 28735 or 29907 alongside a subtalar implant procedure, expect scrutiny. Talk to your billing consultant about how Aetna handles bundling and medically related denials in these scenarios.
Coverage Indications at a Glance
| Indication | Status | Primary ICD-10 Codes | Notes |
|---|---|---|---|
| Subtalar instability | Experimental / Not Covered | M24.871–M24.876, M25.271–M25.279, M25.371–M25.376 | All subtalar implant devices excluded |
| Talipes equinovarus / Clubfoot (congenital) | Experimental / Not Covered | Q66.0, Q66.1, Q66.2 | No coverage regardless of patient age |
| Talipes equinovarus / Clubfoot (acquired) | Experimental / Not Covered | M21.541–M21.549 | No coverage regardless of patient age |
| Foot drop / Dangle foot | Experimental / Not Covered | M21.071–M21.079, M21.371–M21.379, M21.6x1–M21.6x9 | All devices excluded |
| Flatfoot (acquired) — pes planus, pes planovalgus, pes valgus, PTTD | Experimental / Not Covered | M21.40, M21.41, M21.42 | Includes posterior tibial tendon dysfunction |
| Congenital pes planus | Experimental / Not Covered | Q66.50, Q66.51, Q66.52 | No pediatric exception |
| Other congenital valgus deformities of feet | Experimental / Not Covered | Q66.6, Q66.80–Q66.89 | Broad catch-all for congenital presentations |
| Sequela of rickets | Experimental / Not Covered | E64.3 | Listed as associated diagnosis; implant still excluded |
| Any other condition | Experimental / Not Covered | Not specified | Policy explicitly states "not an all-inclusive list" |
Aetna Subtalar Implant Billing Guidelines and Action Items 2025
This policy leaves no room for workarounds. Your action items are about protecting your practice from denials and downstream revenue cycle problems — not about finding a path to coverage.
| # | Action Item |
|---|---|
| 1 | Pull all open Aetna prior authorization requests for CPT 0335T, 0510T, and 0511T before October 8, 2025. If any are pending, withdraw them or expect denials. Notify the ordering provider and document the conversation. |
| 2 | Audit your charge capture for HCPCS S2117. This code maps directly to subtalar arthroereisis. If it appears on any active Aetna fee schedule or chargemaster, flag it as non-covered. Your billing team should not be routing these claims to Aetna without a patient financial agreement in place. |
| 3 | Check CPT 28735 and CPT 29907 claim histories for Aetna. These two codes appear in CPB 0669 as related procedures. If they've been billed alongside subtalar implant codes, review those claims for any pending or recently paid amounts. A modified policy effective date sometimes triggers retroactive review. |
| 4 | Build a non-coverage patient disclosure workflow for Aetna members. Before any subtalar implant procedure, the patient needs to understand Aetna will not pay. Get a signed financial responsibility agreement. Your compliance officer should approve the language. |
| 5 | Update your denial management routing for this policy code. When claims for 0335T, 0510T–0511T, or S2117 come back denied under CPB 0669, route them to write-off — not to appeal. Appealing a blanket experimental designation without new peer-reviewed clinical evidence is a waste of your team's time. The denial is the correct outcome under this coverage policy. |
| 6 | If you see CPT 0335T billed under the ProStop Subtalar Arthroereisis Screw specifically, note that the policy groups 0335T and 0510T–0511T explicitly with that device. The experimental designation holds regardless of the specific device used. |
| 7 | Brief your podiatry and orthopedic surgeons on the effective date. Providers sometimes assume a clinical argument will override a payer's experimental designation. It won't here. Aetna's subtalar implant billing guidelines under CPB 0669 are explicit, and claims submitted after October 8, 2025 face automatic denial. The conversation with your clinical team should happen before that date, not after a claim denial prompts it. |
| 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 Subtalar Implants Under CPB 0669
Category III CPT Codes — Experimental / Not Covered
| Code | Type | Description | Policy Group |
|---|---|---|---|
| 0335T | CPT | Insertion of sinus tarsi implant | Subtalar implants — ProStop Subtalar Arthroereisis Screw |
| 0510T | CPT | Removal of sinus tarsi implant | Subtalar implants — ProStop Subtalar Arthroereisis Screw |
| 0511T | CPT | Removal and reinsertion of sinus tarsi implant | Subtalar implants — ProStop Subtalar Arthroereisis Screw |
HCPCS Code — Not Covered
| Code | Type | Description | Policy Group |
|---|---|---|---|
| S2117 | HCPCS | Arthroereisis, subtalar | HCPCS codes not covered for indications listed in the CPB |
Other CPT Codes Referenced in CPB 0669
| Code | Type | Description | Notes |
|---|---|---|---|
| 28735 | CPT | Arthrodesis, midtarsal or tarsometatarsal, multiple or transverse; with osteotomy (e.g., flatfoot correction) | Related procedure — review claim context carefully |
| 29907 | CPT | Arthroscopy, subtalar joint, surgical; with subtalar arthrodesis | Related procedure — review claim context carefully |
Key ICD-10-CM Diagnosis Codes Under CPB 0669
| Code | Description |
|---|---|
| E64.3 | Sequela of rickets |
| M21.071–M21.079 | Other acquired deformities of ankle and foot — foot drop |
| M21.371–M21.379 | Other acquired deformities of ankle and foot — foot drop |
| M21.40 | Flat foot [pes planus] (acquired), unspecified foot |
| M21.41 | Flat foot [pes planus] (acquired), right foot |
| M21.42 | Flat foot [pes planus] (acquired), left foot |
| M21.541 | Acquired clubfoot, right foot |
| M21.542 | Acquired clubfoot, left foot |
| M21.543 | Acquired clubfoot, unspecified foot |
| M21.544–M21.549 | Acquired clubfoot, additional laterality codes |
| M21.6x1–M21.6x9 | Other acquired deformities — foot drop, additional codes |
| M24.871–M24.876 | Other specific joint derangements — ankle and foot (subtalar instability) |
| M25.271–M25.279 | Joint instability — ankle and foot |
| M25.371–M25.376 | Other joint derangement — ankle and foot |
| Q66.0 | Congenital talipes equinovarus, unspecified foot |
| Q66.1 | Congenital talipes equinovarus, right foot |
| Q66.2 | Congenital talipes equinovarus, left foot |
| Q66.50 | Congenital pes planus, unspecified foot |
| Q66.51 | Congenital pes planus, right foot |
| Q66.52 | Congenital pes planus, left foot |
| Q66.6 | Other congenital valgus deformities of feet |
| Q66.80 | Other congenital deformities of feet, unspecified |
| Q66.81–Q66.89 | Other congenital deformities of feet, additional codes |
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