Primary open surgical repair of a torn collateral ligament and/or knee joint capsule, performed acutely following injury.

Verified May 8, 2026 · 5 sources ↓

Medicare: $637.29
Total RVUs: 19.08
Global, days: 90
Region: Knee

Drawn from AAPCFindacodeIlmeridianCMS

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Specify which ligament(s) were repaired: medial collateral, lateral collateral, and/or capsule — vague references to 'knee ligament' are insufficient for audit.
Confirm the repair was primary (direct tissue repair at time of or shortly after injury), not a reconstruction or augmentation with graft material.
Document the mechanism and timing of injury to establish acute presentation and medical necessity for primary rather than staged repair.
Identify the surgical approach used — e.g., open medial or lateral arthrotomy — not just 'standard approach'; audit reviewers flag operative notes that omit this.
If additional ligament repairs or reconstructions were performed in the same session, document each structure separately with the rationale for combined procedures.
Record laterality explicitly (left vs. right knee) in both the operative note and on the claim.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 58 Staged or related 59 Distinct service 62 Co-surgeons LT Left side RT Right side 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 27405 covers primary open repair of a torn collateral ligament — medial (MCL) or lateral (LCL) — and/or the knee joint capsule. 'Primary' means the surgeon is directly repairing the torn tissue at or near the time of injury, not reconstructing it with a graft. This distinguishes 27405 from the reconstruction/augmentation codes in the 27427–27429 range, which apply when native tissue is insufficient and graft material is used.

When multiple ligaments are repaired in the same session, code selection gets more specific: 27407 covers primary cruciate repair, and 27409 covers collateral and cruciate repair together. If you're billing a collateral repair alongside a cruciate repair, use modifier 51 on the lower-value code and consider modifier 59 to establish distinct procedural identity. Per AAPC orthopedic coding guidance, primary ligament repair performed via arthrotomy can be billed separately from a reconstruction when both are legitimately performed.

This code carries a 90-day global period. All routine post-op visits, wound checks, and dressing changes through day 90 are bundled. Unrelated problems in that window require modifier 24 (E/M) or 79 (unrelated procedure). A staged or planned return for related work — such as a subsequent reconstruction if primary repair fails — uses modifier 58.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	8.85
Practice expense RVU	8.43
Malpractice RVU	1.8
Total RVU	19.08
Medicare national rate	$637.29
Global period	90 days

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

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$637.29
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI A2) Ambulatory surgical center (freestanding)	$3,695.53

Common denial reasons

The recurring reasons claims for CPT 27405 get rejected.

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

Wrong code selected: 27405 (collateral) used when a cruciate was repaired — use 27407 for cruciate or 27409 for both collateral and cruciate.
Bundling denial when 27405 is billed alongside arthroscopic codes without modifier 59 establishing a distinct open repair separate from any scope work.
Missing or insufficient medical necessity documentation — acute injury diagnosis not clearly tied to operative findings in the note.
Laterality missing from the claim when payer requires LT or RT modifier for unilateral procedures.
Global period conflict: post-op E/M billed without modifier 24 when a related visit falls within the 90-day global window.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01When do I use 27405 versus 27407 or 27409?

27405 is for collateral ligament (MCL or LCL) and/or capsule repair only. 27407 covers primary cruciate (ACL or PCL) repair. 27409 applies when both collateral and cruciate ligaments are repaired in the same session. If your operative note documents only a collateral repair, 27405 is correct — do not default to 27409 unless a cruciate was also addressed.

02Can 27405 be billed with arthroscopic knee codes on the same day?

It can, but expect scrutiny. If an arthroscopy was used as a diagnostic adjunct and the definitive repair was performed open, document both components clearly and apply modifier 59 to the arthroscopic code to indicate a distinct procedural service. Medicare in particular may question why both were necessary — justify in the operative note.

03What modifier applies if I need to return for a related procedure during the 90-day global?

Use modifier 78 for an unplanned return to the OR for a complication or related procedure during the global period. If the return was planned or staged from the outset — for example, a planned reconstruction after primary repair — use modifier 58 instead. Do not invert these.

04Is 27405 ever appropriate for arthroscopic collateral repair?

No. 27405 is an open procedure code. There is no dedicated CPT code for arthroscopic isolated collateral ligament repair; per AAPC orthopedic coding guidance, unlisted code 27599 with thorough documentation is the correct route for isolated arthroscopic MCL or LCL repair.

05How does the 90-day global affect billing for physical therapy or follow-up E/M visits?

The 90-day global bundles the surgeon's own post-op E/M visits for related issues — not physical therapy, which is billed separately by the treating therapist. If the surgeon sees the patient during the global for a completely unrelated problem, append modifier 24 to the E/M and document the unrelated diagnosis clearly.

06Can 27405 be billed bilaterally?

Bilateral collateral ligament injury is rare, but if both knees are repaired in the same session, bill 27405 with modifier 50, or with separate LT and RT line items depending on payer preference. Verify your specific payer's bilateral billing policy before submitting — some commercial payers do not follow the Medicare modifier 50 convention.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira's AI scribe captures the specific ligament repaired (MCL, LCL, or capsule), confirms the repair was primary direct tissue repair versus graft reconstruction, documents the surgical approach by name, and flags laterality from dictation. This prevents the most common 27405 audit failure: an operative note that says 'knee ligament repair' without specifying collateral versus cruciate — the distinction that separates 27405, 27407, and 27409.

See how Mira captures CPT 27405 documentation