Open intra-articular ligamentous reconstruction or augmentation of the knee joint

Verified May 8, 2026 · 5 sources ↓

Medicare: $1,040.44
Total RVUs: 31.15
Global, days: 90
Region: Knee

Drawn from CMSAbosCgsmedicareAAPC

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Specify open intra-articular approach explicitly — do not write 'standard approach' or leave approach unnamed
Identify the ligament(s) reconstructed and graft type (autograft, allograft, synthetic augmentation)
Pre-operative imaging (X-ray or MRI) demonstrating ligamentous injury, instability, or structural failure
Document prior conservative treatment attempted or clinical rationale for bypassing conservative care
Note whether reconstruction is intra-articular only (27428) vs. combined intra- and extra-articular (27429)
If Medicare patient, document that indications meet CMS LCD A57428 criteria or provide explicit physician rationale referencing clinical guidelines

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 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 27428 covers open, intra-articular ligamentous reconstruction or augmentation of the knee — most commonly ACL reconstruction performed through an open approach rather than arthroscopically. The defining features are the open surgical technique and the intra-articular placement of the graft or augmentation construct. When both intra-articular and extra-articular reconstruction are performed in the same session, report 27429 instead; when only extra-articular augmentation is performed, report 27427. Choosing the wrong code in this family is one of the most common errors on knee ligament claims.

The 90-day global period means all routine post-op care through day 90 is bundled into the payment. Separate E/M visits within that window require modifier 24 (unrelated condition) or modifier 25 (significant, separate problem on the same day as a procedure). Staged or planned secondary procedures in the global window need modifier 58; unplanned returns for related complications use modifier 78; unrelated procedures use modifier 79.

For Medicare coverage under CMS LCD A57428, the record must support advanced joint or ligamentous pathology — typically with imaging demonstrating instability, structural failure, or prior failed conservative management. If the patient does not meet standard indications, the physician's clinical rationale must be explicitly stated in the pre-procedure note, referencing evidence-based guidelines or published literature.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	15.19
Practice expense RVU	12.73
Malpractice RVU	3.23
Total RVU	31.15
Medicare national rate	$1,040.44
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	$1,040.44
HOPD (APC 5115) Hospital outpatient department	$13,116.76
ASC (PI J8) Ambulatory surgical center (freestanding)	$8,621.29

Common denial reasons

The recurring reasons claims for CPT 27428 get rejected.

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

Wrong code selection: arthroscopic ACL reconstruction should be 29888, not 27428 — open vs. arthroscopic distinction is the most common mismatch
Missing or insufficient pre-op imaging documentation required by CMS LCD A57428
Conservative treatment not documented or absence not explained, triggering medical necessity denial
Procedure billed as 27428 when both intra- and extra-articular reconstruction were performed — should be 27429
Global period violation: post-op E/M billed without modifier 24 during the 90-day window

Frequently asked questions

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

01When should I use 27428 vs. 29888?

Use 27428 for open intra-articular knee ligament reconstruction. Use 29888 for arthroscopically assisted ACL reconstruction. The surgical approach drives the code — if the operative note describes an arthroscopic technique, 27428 is incorrect.

02What's the difference between 27427, 27428, and 27429?

27427 = extra-articular only. 27428 = intra-articular only (open). 27429 = combined intra-articular and extra-articular in the same session. If your operative note documents both components, bill 27429, not 27428 with an add-on.

03Can I bill a same-day E/M with 27428?

Yes, with modifier 25 on the E/M if you're seeing the patient for a significant, separately identifiable problem on the same day as the procedure. Without modifier 25, the E/M bundles into the surgical payment.

04What imaging does Medicare require to support 27428?

CMS LCD A57428 requires X-ray or MRI demonstrating structural pathology — joint space narrowing, ligamentous disruption, subluxation, or equivalent findings. Pre-op imaging that does not clearly support the indication is a top audit trigger.

05How do I handle a complication requiring return to the OR during the 90-day global?

If you return for a complication related to the original procedure, use modifier 78. If the return is for a completely unrelated problem, use modifier 79. Do not bill either return-to-OR scenario without a modifier — it will deny as a global period duplicate.

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

No — if both intra-articular and extra-articular work is done in the same session, the correct code is 27429. Billing 27427 and 27428 together for the same knee same day is incorrect coding and will draw NCCI scrutiny.

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 surgical approach (open), graft type and source, specific ligament(s) addressed, and whether reconstruction was intra-articular only or combined with extra-articular work — the distinction that determines whether 27428 or 27429 is correct. It also flags when the dictation describes an arthroscopic technique, prompting review of 29888 instead. This prevents the most common denial on knee ligament claims: approach-code mismatch.

See how Mira captures CPT 27428 documentation