Open extra-articular ligamentous reconstruction of the knee, with or without graft augmentation, performed outside the joint capsule.

Verified May 8, 2026 · 5 sources ↓

Medicare: $662.67
Total RVUs: 19.84
Global, days: 90
Region: Knee

Drawn from CMSKzanowAAOS

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Specify graft type by name — autograft (donor site) or allograft — and distinguish it from any synthetic tape or suture augmentation used in the same case
Name the specific ligament(s) reconstructed (e.g., medial collateral, lateral collateral, posterolateral complex) and their anatomic location relative to the joint capsule (extra-articular)
Document the fixation method: screw type, size, and placement site for graft anchoring
Include pre-operative diagnosis supported by imaging (MRI preferred) confirming ligament insufficiency or failure of prior repair
If billing with a second knee procedure same-day, document medical necessity and distinct procedural service for each code
Record whether the procedure is a primary reconstruction or revision following prior ligament surgery, as payers may require prior auth differentiation

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 59 Distinct service 62 Co-surgeons 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 27427 covers open reconstruction of the extra-articular ligaments of the knee — those structures located outside the joint capsule, such as the medial or lateral collateral ligaments. The procedure requires biologic tissue: an autograft harvested from the patient or an allograft from a donor. Synthetic tape or suture augmentation alone does not meet the threshold for reconstruction; that work codes as repair. If the operative note describes both repair and reconstruction in the same session, the documentation must clearly distinguish the biologic graft placement from any supplemental fixation material.

The 90-day global period applies. All routine post-op care, wound checks, and hardware-related visits through day 90 are bundled. Separate E/M services in that window require modifier 24 (unrelated medical problem) or 25 (significant, separately identifiable E/M on the day of a minor procedure — not applicable here given the 090 global).

Critical NCCI bundling rule: arthroscopic ligament reconstruction codes 29888 and 29889 are bundled into 27427 and cannot be reported together on the same encounter. If you're billing a same-day knee arthroscopy, confirm it is a distinct, separately documented service before appending modifier 59 or an X-modifier — and check current NCCI PTP edits before billing.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	9.55
Practice expense RVU	8.42
Malpractice RVU	1.87
Total RVU	19.84
Medicare national rate	$662.67
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	$662.67
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI J8) Ambulatory surgical center (freestanding)	$4,859.27

Common denial reasons

The recurring reasons claims for CPT 27427 get rejected.

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

Operative note describes suture tape or synthetic augmentation only — payers deny 27427 when no biologic graft is documented
29888 or 29889 billed same-day without recognizing NCCI bundle into 27427 — edit triggers automatic denial of the arthroscopy code
Modifier 59 or LT/RT missing when billing bilateral or same-session procedures, causing claim to reject as duplicate
Insufficient pre-op imaging or clinical documentation of chronic instability or failed conservative treatment to support medical necessity
Repair and reconstruction conflated in operative note — payer downcodes to 27405 (repair) when graft use is ambiguous

Frequently asked questions

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

01Does suture tape or internal brace augmentation qualify for CPT 27427?

No. 27427 requires biologic tissue — autograft or allograft — to replace or reconstruct the ligament. Suture tape or synthetic augmentation added to protect a repair does not meet the reconstruction threshold. That work codes as ligament repair (e.g., 27405).

02Can 29888 or 29889 be billed with 27427 on the same date?

No. Per NCCI policy, arthroscopic ligament reconstruction codes 29888 and 29889 are bundled into 27427. The CPT parenthetical instructs that those arthroscopy codes should not be used with reconstruction procedures 27427–27429.

03What modifier applies when 27427 is performed bilaterally in the same session?

Report 27427 with modifier 50 and one unit of service for bilateral same-session procedures. Do not submit two separate line items with LT and RT; Medicare expects the 50 modifier format with a single unit.

04How do you bill an unplanned return to the OR for a wound complication during the 90-day global?

Use modifier 78 for an unplanned return to the operating room for a procedure related to the original surgery within the global period. Modifier 79 applies if the return procedure is entirely unrelated to the original reconstruction.

05When is modifier 22 appropriate for 27427?

Append modifier 22 when the reconstruction required substantially more work than typical — for example, severe scarring from prior surgery, complex multiligament involvement, or difficult graft harvest. Support it with a separate operative note paragraph quantifying the additional time and complexity; payers will request documentation before paying the upcharge.

06Can 27427 and 27428 be billed together for the same knee on the same day?

27427 covers extra-articular reconstruction and 27428 covers intra-articular reconstruction. If both are genuinely performed on the same knee during the same session, report them with modifier 51 on the lower-RVU code. Verify NCCI PTP edits for the current quarter before billing both.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures graft source (autograft vs. allograft), harvest site if autograft, specific ligament(s) reconstructed, fixation hardware details, and explicit extra-articular anatomic location from surgeon dictation. This prevents the most common audit flag on 27427 — operative notes that describe suture tape augmentation but omit biologic graft documentation, which causes payers to deny reconstruction-level reimbursement and downcode to repair.

See how Mira captures CPT 27427 documentation