Arthroplasty of the femoral condyles or tibial plateau(s) of the knee, without debridement or partial synovectomy.

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 5 cited references ↓

• Specify the anatomic target: femoral condyle(s), medial tibial plateau, lateral tibial plateau, or combination — vague references to 'knee joint' are insufficient.
• Confirm the procedure did NOT include debridement or partial synovectomy; if it did, 27443 is the correct code.
• Document the implant system, component type, and lot/serial numbers per facility and payer implant-log requirements.
• Record the surgical approach by name (e.g., medial parapatellar, subvastus, midvastus); operative notes that state only 'standard approach' are audit flags.
• State the indication with supporting pre-op imaging findings — isolated compartment disease, prior failed conservative treatment, and patient functional status.
• If billing same-day with any arthroscopic or other knee procedure, document distinct anatomic sites or separate operative steps to support unbundling with the appropriate modifier.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Common denial reasons

The recurring reasons claims for CPT 27442 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

• Code billed when debridement or partial synovectomy was also performed — payers recode or deny in favor of 27443.
• 27442 and 27441 billed together on the same date for the same knee — these are NCCI mutually exclusive code pairs; only one is payable.
• Operative note documents bilateral involvement but modifier 50 or LT/RT laterality modifiers were not appended, triggering a laterality mismatch denial.
• Post-op E/M visit billed without modifier 24 during the 90-day global period, resulting in automatic bundling denial.
• Implant documentation missing or incomplete in the facility record, causing payer audits to recoup payment or deny the claim outright.
• Insufficient pre-operative documentation of compartment-specific disease to establish medical necessity for partial rather than total knee arthroplasty.