CMS NCD 285: Arthroscopic Lavage and Debridement for Osteoarthritic Knee Coverage Policy (2026)

CMS has issued a modified version of National Coverage Determination (NCD) 285, governing Medicare coverage for arthroscopic lavage and arthroscopic debridement procedures performed on patients with osteoarthritis of the knee. The policy draws a firm line between covered and noncovered indications—and the distinctions matter enormously for claim approval and denial management. Orthopedic billing teams and RCM directors at practices performing knee arthroscopy should review this policy carefully before submitting claims for Medicare beneficiaries.

What CMS NCD 285 Covers—and What It Doesn't

The Centers for Medicare & Medicaid Services has been unambiguous: there are no nationally covered indications for arthroscopic lavage or arthroscopic debridement when used to treat osteoarthritis of the knee. The clinical evidence simply hasn't supported coverage. CMS determined, after consulting clinical investigators and the orthopedic community, that these procedures are not reasonable or necessary for the osteoarthritic knee under the conditions specified below.

That said, "not covered under NCD 285" does not mean "never covered." A distinct subset of patients may still qualify for coverage under local Medicare Administrative Contractor (MAC) discretion—but the criteria are specific, and documentation requirements are real.

CMS Medicare Noncovered Indications: The Three Hard Stops

CMS identifies three categories of procedures that Medicare will not cover under this NCD, regardless of clinical circumstance:

1. Arthroscopic lavage used alone for the osteoarthritic knee.
Saline irrigation of the knee joint—whether high or low volume—performed as a standalone treatment for osteoarthritis is not covered. Current clinical practice does not recognize a benefit from lavage alone in reducing mechanical symptoms.

2. Arthroscopic debridement for osteoarthritic patients presenting with knee pain only.
If the clinical picture is knee pain without additional mechanical symptoms, debridement will not be covered. Pain alone is not sufficient to meet medical necessity criteria under this policy.

3. Arthroscopic debridement and lavage for patients with severe osteoarthritis.
CMS defines "severe osteoarthritis" using the Outerbridge classification scale. Grades III and IV—cartilage fragmentation or fissuring in an area greater than 1 cm, and cartilage erosion down to bone, respectively—constitute severe disease. Procedures on patients meeting this threshold are noncovered under Medicare.

For billing teams: if any one of these three conditions applies, the claim will not pass national coverage review. Document your pre-procedure evaluation accordingly.

Who May Still Qualify: Local MAC Discretion for Knee Debridement

Here's where the policy creates an important carve-out that billing teams must understand. CMS explicitly leaves coverage determinations at local contractor discretion for a defined subpopulation:

Patients without severe osteoarthritis (i.e., Outerbridge Grades I–II) who present with symptoms beyond pain alone may qualify for coverage. The policy specifically identifies three qualifying symptom categories:

• Mechanical symptoms — locking, snapping, or popping of the knee joint
• Limb and knee joint alignment issues
• Less severe or early degenerative arthritis

For these patients, your MAC has the authority to cover arthroscopic debridement—but may require documentation. CMS specifies that MACs may ask for one or all of the following:

• Operative notes
• Reports of standing X-rays
• Arthroscopy results

Check your specific MAC's local coverage determination (LCD) before assuming coverage. Do not rely solely on the NCD.

Understanding the Osteoarthritis Diagnosis Criteria Under NCD 285

For Medicare patients, the diagnosis of osteoarthritis of the knee follows American College of Rheumatology criteria. A qualifying diagnosis requires knee pain plus at least five of the following nine criteria:

• Age over 50
• Morning stiffness lasting fewer than 30 minutes
• Crepitus on active motion
• Bony tenderness
• Bony enlargement
• No palpable warmth of the synovium
• ESR less than 40 mm/hr
• Rheumatoid Factor less than 1:40
• Synovial fluid signs of osteoarthritis

Billing teams should confirm that the medical record documents the clinical basis for the osteoarthritis diagnosis—not just the diagnosis code. If the chart doesn't reflect the ACR criteria, you're exposed on audit.

Affected Codes

This policy does not list specific CPT or HCPCS codes. CMS has not published procedure-specific billing codes within NCD 285. Billing teams should reference their MAC's LCD and the applicable CPT codes for knee arthroscopy procedures (typically found in the musculoskeletal surgery section of the CPT code set) and confirm coverage status at the local level.

Related ICD-10 Diagnosis Codes — while not enumerated in the NCD itself, the following diagnosis codes are directly relevant to this policy and should be reviewed for accurate claim submission:

Note: These ICD-10 codes are provided as clinical reference based on the conditions described in NCD 285. They are not enumerated within the policy document itself. Confirm code selection with your coding team.

What Your Billing Team Should Do