CurrentPremera BluecrossPolicy 7.01.48

Cartilage Lesions — Autologous Chondrocyte Implantation (ACI/MACI)

Defines medical necessity, site-of-service, documentation, and coding for autologous chondrocyte implantation (including MACI) for focal full‑thickness knee cartilage lesions and states investigational use for other joints; intended for providers and reviewers.

Policy Summary

PayerPremera Bluecross

PolicyCartilage Lesions — Autologous Chondrocyte Implantation (ACI/MACI)

Policy CodePolicy 7.01.48

Change TypeAdministrative (no material clinical changes)

Effective DateNov 7, 2025

Next Review Date

Key ActionObtain prior authorization and submit documentation demonstrating that medical necessity criteria (age, lesion size, location, and prior treatments) are met.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

>=1.5minimum lesion size for coverage

<4consider marrow stimulation if

FDA-approvedMACI regulatory status

15-55age range considered

Coverage Criteria for Autologous Chondrocyte Implantation (ACI / MACI)

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

Autologous chondrocyte implantation (MACI) — Medical Necessity

Covered when ALL of the following are met

Age and clinical status: Individual is skeletally mature (e.g., documented growth plate closure, typically >= 15 years) OR an adult who is too young to be an appropriate candidate for total knee arthroplasty or other reconstructive knee surgery (e.g., < 55 years)age 15-55 considered

Adolescents should have documented growth plate closure

Symptoms: Severe, disabling knee pain and loss of knee function from acute or repetitive trauma that interferes with activities of daily living or work ability

Lesion characteristics: Focal, full-thickness (Outerbridge grade III or IV) unipolar lesions of the weight-bearing surface of the femoral condyles, trochlea, or patella that are at least 1.5 cm2 in size>= 1.5 cm2

Document minimal to absent degenerative changes in surrounding cartilage (Outerbridge grade II or less) and normal-appearing hyaline cartilage at the defect border

Joint condition: Knee is stable with intact or reconstructed ligaments (or ligament repairs planned concurrently), has normal joint alignment, and normal joint space

Misalignment and instability are contraindications unless corrected concurrently

Coverage rationale and constraints

Summary and regulatory/guideline context informing coverage

Evidence summary for joints other than knee: For focal articular cartilage lesions of joints other than the knee, available evidence (case series, systematic reviews of case series, network meta-analyses and retrospective studies) is insufficient to determine that ACI improves net health outcome; the talus has the greatest body of literature outside the knee.

Supports restrictive coverage for non-knee joints (consider investigational)

Knee-specific regulatory criteria: MACI is FDA-approved for repair of symptomatic, single or multiple full-thickness cartilage defects of the knee in adults; NICE recommends ACI as an option for femoral condyle and patella defects only when the defect is > 2 cm2, there has been no prior surgery to repair articular cartilage defects, and there is minimal osteoarthritic damage.defect >2 cm2; no prior cartilage repair

Regulatory and guideline constraints should inform coverage decisions and prior authorization review

Autologous chondrocyte implantation (ACI), including matrix-associated ACI (MACI), is considered investigational for the treatment of focal articular cartilage lesions in joints other than the knee (including the talus/ankle) and for any indications not explicitly listed as covered. The policy’s evidence review found only case series, systematic reviews of case series, and retrospective studies for non‑knee joints, with the greatest body of literature for the talus, and concluded the evidence is insufficient to determine that ACI improves net health outcome for these sites.

Procedures and indications that are not described in the knee-specific medical necessity criteria (e.g., unipolar, full‑thickness femoral condyle, trochlea, or patellar defects meeting size and other criteria) are classified as investigational and are not supported by the current evidence base.

Use of ACI for focal cartilage lesions outside the knee is not supported by adequate comparative evidence. The summary of evidence notes the available literature for non‑knee joints consists primarily of case series and noncomparative designs, and explicitly states that comparative trials are needed to determine whether ACI improves outcomes in these locations.

Because of this insufficiency of evidence, ACI for non‑knee joints may be subject to investigational or exclusionary coverage determinations and potential claim denial when submitted for those anatomic sites.

Prior authorization is required for elective ACI procedures and site‑of‑service review. When evaluating site of service for elective surgical procedures, reviewers should apply the policy’s site‑of‑service medical necessity criteria (for example, comorbid conditions, anesthesia or cardiovascular risk, morbid obesity, pregnancy, bleeding disorders, anticipated transfusion need, and facility type) to determine whether inpatient or outpatient hospital settings are medically necessary.

If an elective ACI is proposed in a site that does not meet the policy’s site‑of‑service criteria (for example, performing the procedure in an outpatient hospital department when criteria for outpatient ASC are not met), the site-of-service determination may render the service not medically necessary and impact authorization or payment.

The policy reiterates that evidence for ACI in joints other than the knee is insufficient to demonstrate an improvement in net health outcome. Given this evidence gap, ACI performed for non‑knee joints may be classified as investigational and could be denied as not medically necessary depending on the clinical circumstances and documentation provided.

Providers requesting authorization for ACI in non‑knee joints should be aware that the policy’s stance is restrictive and that supporting comparative outcome data are lacking for these anatomic sites.

Coding and Procedure Codes

Covered CPT CodesCPTCovered

27412

Autologous chondrocyte implantation, knee

Related Arthroscopy CPT CodesCPT

29877	Arthroscopy, knee, surgical; debridement/shaving of articular cartilage (chondroplasty)
29879	Arthroscopy, knee, surgical; abrasion arthroplasty (includes chondroplasty where necessary) or multiple drilling or microfracture
29880	Arthroscopy, knee, surgical; with meniscectomy (medial AND lateral, including any meniscal shaving) including debridement/shaving of articular cartilage (chondroplasty), same or separate compartment(s), when performed
29881	Arthroscopy, knee, surgical; with meniscectomy (medial OR lateral, including any meniscal shaving) including debridement/shaving of articular cartilage (chondroplasty), same or separate compartment(s), when performed
29882	Arthroscopy, knee, surgical; with meniscus repair (medial OR lateral)
29883	Arthroscopy, knee, surgical; with meniscus repair (medial AND lateral)

HCPCS Codes / Secondary Procedure CodesHCPCS

J7330	Autologous cultured chondrocytes, implant
S2112	Arthroscopy, knee, surgical, for harvesting of cartilage (chondrocyte cells)

Clinical trial identifiersmixed

NCT04785092	Clinical trial identifier listed in ongoing trials table
NCT03219307	Clinical trial identifier listed in ongoing trials table
NCT04744402	Clinical trial identifier listed in ongoing trials table
NCT01957722	Clinical trial identifier listed in ongoing trials table
NCT05651997	Clinical trial identifier listed in ongoing trials table
NCT05402072	Clinical trial identifier listed in ongoing trials table
NCT01656902	Clinical trial identifier listed in ongoing trials table

Named products / devicesmixed

MACI	Autologous cultured chondrocytes on a porcine collagen membrane (FDA-approved product name)
Agili-C	Agili-C osteochondral scaffold implant (FDA-approved device name)

Removed CPT codes (historical)CPT

29870

Arthroscopy, knee, surgical; abrasion arthroplasty (subchondral drilling, microfracture)

Removed HCPCS codes (historical)HCPCS

S2112

Removed HCPCS code S2112 (historical)

Coding updatesCPT

29870

CPT code 29870 removed per 04/01/26 coding update

Lesion size for coverage

Minimum lesion size for coverage>= 1.5 cm2 (focal, full-thickness Outerbridge grade III or IV unipolar lesions of weight-bearing femoral condyles, trochlea, or patella)

Surrounding cartilage requirementMinimal to absent degenerative changes (Outerbridge grade II or less) at defect margins

Joint selectionLesion must be on weight-bearing surface of femoral condyles, trochlea, or patella

Lesion size where marrow stimulation may be tried first

Lesion size where marrow stimulation is preferred first< 4 cm2 — consider marrow-stimulating techniques (e.g., microfracture) before ACI if prior treatment was only debridement

Average defect size in literatureAverage reported defect ~5 cm2; studies included lesions up to ~15 cm2

Prior treatment considerationIf only prior surgery was debridement, marrow stimulation may be tried for smaller defects before ACI

Age threshold (historical)

Historical age threshold updateAge criterion updated in 2019 to 15 years of age or older (replacing prior 16-year threshold)

Age range considered in policy contextPolicy considers skeletally mature individuals and adults too young for arthroplasty (e.g., <55 years)

Adolescent documentation noteAdolescents should have documented growth plate closure when applicable

Provider Actions, Prior Authorization, and Documentation Requirements

Prior Authorization

Prior Authorization Required — Indication and Product Verification

Prior authorization is required and must verify both the clinical indication for ACI and the specific product to be used. Requests should document that the proposed use aligns with FDA-approved indications (e.g., MACI for knee cartilage defects) or clearly identify investigational status for non‑approved products.

Submit documentation showing the lesion meets coverage criteria (size, Outerbridge grade, location).
Identify the ACI product by name (e.g., MACI) and state whether use is within FDA indication or investigational.
If a non‑FDA ACI product or an ACI technique for joints other than the knee is proposed, note that these indications are considered investigational and may be denied.

Prior Authorization

Site‑of‑Service Review and Prior Authorization

Effective Nov 7, 2025, the site‑of‑service review will incorporate ASC-specific criteria and related policy requirements. Prior authorization must include justification for the proposed site of service (ASC vs hospital outpatient) and documentation that site criteria are met.

If the procedure is proposed in an ASC, include documentation that the ASC meets the related ASC Select Surgical Procedures criteria.
If an on‑ or off‑campus hospital outpatient site is proposed, document why ASC placement is not appropriate or available.
Site‑of‑service review does not apply to Indian Health Services (IHS) facilities per June 1, 2026 update.

Denial Risk

Site‑of‑Service Noncompliance — Denial Risk

Performing an elective ACI procedure in a site that does not meet the documented site‑of‑service criteria may be considered not medically necessary and is subject to denial. Prior authorization approval does not guarantee payment if the service is ultimately performed in a non‑covered site.

Elective procedures performed in a non‑approved site when criteria are unmet may be denied.
Providers are responsible for verifying site eligibility prior to scheduling to avoid denial risk.

Billing Rule

Coding and Site‑of‑Service Mismatch — Billing Rule and Audit Risk

Ensure coding and charge submissions match the authorized service and site of service. Mismatches between approved codes, billed codes, or site‑of‑service (e.g., ASC vs HOPD) may trigger audits, claim denials, or requests for additional documentation.

Use the CPT/HCPCS codes consistent with the approved ACI procedure and any concurrent arthroscopy codes.
Avoid changing the site of service after authorization without obtaining reapproval.
Coding discrepancies identified in history updates have previously prompted coding and site‑of‑service reviews.

Documentation Required

Required Clinical Documentation — Product and Lesion Details

Providers must document the specific ACI product and all current clinical information supporting medical necessity. The submitted record should include a clear lesion description, Outerbridge grade, and prior surgical history.

Document the specific ACI product name (e.g., MACI) and its FDA indication or note investigational status.
Office visit notes should include age, lesion size and description, Outerbridge grade, surrounding cartilage appearance, and whether growth plates are closed for adolescents.
Include imaging reports and operative notes describing prior procedures (e.g., debridement, microfracture).

Documentation Required

Submit Current Documentation

Submit current, complete documentation consistent with the most recent policy updates when requesting authorization or appeal. Incomplete or outdated documentation may delay review or result in denial.

Provide up‑to‑date office notes, imaging, and operative reports at the time of authorization.
If policy changes affect site‑of‑service or coding (see History entries), include documentation addressing those changes.

Note

Consider Prior Less‑Invasive Cartilage Repair Before ACI

Reviewers should confirm prior less‑invasive cartilage repair attempts before approving ACI for smaller defects. For lesions < 4 cm2 with only prior debridement, consider marrow‑stimulating techniques (e.g., microfracture) before ACI.

If prior treatment was limited to debridement, document consideration of or attempt at marrow stimulation for lesions < 4 cm2.
If prior cartilage repair surgery was performed (other than debridement), document type and date to verify eligibility per NICE and policy criteria.

Background and Rationale

Articular cartilage has limited intrinsic healing capacity; focal full‑thickness defects can cause pain, loss of function, and progressive osteoarthritis. Autologous chondrocyte implantation (ACI) techniques harvest a patient’s chondrocytes, expand them in culture, and implant them into full‑thickness cartilage defects with the goal of regenerating hyaline‑like repair tissue. Matrix‑associated ACI (MACI) uses a scaffold to facilitate implantation and avoid periosteal patching, and is the commercially available, FDA‑recognized method for knee defects.

Definitions and Key Terms

Modified Outerbridge Classification

Grade IMRI: focal areas of hyperintensity with normal contour; Arthroscopy: cartilage softening and swelling

Grade IIMRI: blister-like swelling/fraying extending to surface; Arthroscopy: fragmentation and fissuring

Grade IIIMRI: partial-thickness cartilage loss with focal ulceration; Arthroscopy: partial-thickness loss with fibrillation

Grade IVMRI: full-thickness cartilage loss with underlying bone reactive changes; Arthroscopy: cartilage destruction with exposed subchondral bone

ASA and NYHA classifications

ASA classificationASA I–V used for anesthesia risk (I = healthy patient; II = mild systemic disease; III = severe systemic disease; IV = severe disease that is a constant threat to life; V = moribund)

NYHA classificationNYHA Classes I–IV for heart failure functional status (I = no symptoms; II = mild; III = marked limitation; IV = symptoms at rest)

Use in site-of-service assessmentASA and NYHA classes are used to help assess perioperative site-of-service risk

MACI definition

DefinitionMatrix-induced autologous chondrocyte implantation (MACI) consists of autologous chondrocytes cultured onto a bioresorbable porcine-derived collagen membrane

Regulatory statusMACI received FDA approval in December 2016 for repair of symptomatic, single or multiple full-thickness cartilage defects of the knee in adults

Procedure steps (overview)Involves biopsy, chondrocyte culturing on matrix, implantation via arthrotomy, and postsurgical rehabilitation

Agili-C definition

DefinitionAgili-C is a proprietary biocompatible, biodegradable tapered-shape osteochondral implant that acts as a 3-dimensional scaffold when placed in a pre-prepared osteochondral hole

FDA regulatory noteAgili-C was granted FDA breakthrough status and approved in 2021 for treatment of knee-joint surface lesions sized 1 to 7 cm2 without severe osteoarthritis

Intended effectDesigned to support regeneration of articular cartilage and underlying subchondral bone

Matrix-associated ACI (MACI) — alternate naming/description

Alternate name/techniqueMatrix-associated autologous chondrocyte implantation (MACI) — A form of ACI using a scaffold/matrix to deliver cultured chondrocytes for cartilage repair

Clinical evidenceStudied in randomized trials and long-term follow-up showing clinical outcomes for knee defects

PurposeScaffold-based approach simplifies implantation and aims to regenerate hyaline-like cartilage compared with traditional periosteal patch ACI