Open surgical treatment of patellar dislocation, with or without partial or complete removal of the patella.

Verified May 8, 2026 · 5 sources ↓

Medicare: $826.67
Total RVUs: 24.75
Global, days: 90
Region: Knee

Drawn from AAPCCMSMdclarity

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Confirm acute versus recurrent dislocation — recurrent cases do not map to 27566
Specify laterality (left or right knee) to satisfy ICD-10 requirements and avoid claim-level edits
Document whether open reduction alone was performed or whether partial or total patellectomy was included
Record the surgical approach and findings at the time of open reduction, including status of articular cartilage and retinacular structures
Note any failed closed reduction attempts that necessitated open treatment
Document anesthesia type, patient positioning, and any concomitant procedures performed at the same session

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 58 Staged or related 59 Distinct service 76 Repeat, same physician 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 27566 covers open reduction of an acute patellar dislocation through a surgical incision, allowing direct visualization and realignment of the kneecap. The procedure may include partial or total patellectomy when the patella is too damaged to preserve. It sits at the top of the patellar dislocation code family — 27560 (closed, no anesthesia) and 27562 (closed, with anesthesia) are the non-operative alternatives; 27566 is the open surgical option reserved for cases where closed reduction fails or is not appropriate.

For recurrent dislocations, 27566 is not the right code — those cases map to reconstruction codes such as 27420–27424. Use 27566 only for acute traumatic dislocation treated operatively. ICD-10 laterality is required; missing side specificity is a top claim-level edit trigger. The 90-day global period means all routine post-op care through day 90 is bundled — bill modifier 24 for unrelated E/M visits and modifier 79 for unrelated procedures performed during the global window.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	12.39
Practice expense RVU	9.73
Malpractice RVU	2.63
Total RVU	24.75
Medicare national rate	$826.67
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	$826.67
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 27566 get rejected.

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

Missing or non-specific ICD-10 laterality code — payers require left/right designation
27566 billed for recurrent patellar dislocation, which maps to reconstruction codes (27420–27424), not this code
Concomitant procedures billed without modifier 51 or without meeting NCCI bundling criteria for separate service
Closed treatment codes (27560/27562) and 27566 billed for the same encounter without documentation justifying open approach
Post-operative E/M visits billed without modifier 24 during the 90-day global period

Frequently asked questions

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

01Can I bill 27566 for a recurrent patellar dislocation?

No. 27566 is for acute traumatic dislocation treated with open reduction. Recurrent patellar dislocation maps to reconstruction codes in the 27420–27424 range. Document the chronicity clearly in the operative note so the code selection is defensible.

02What is the global period for 27566 and what does it include?

27566 carries a 90-day global period. That bundles the surgery, the day-before preoperative visit, and all routine post-op care through day 90 — including dressing changes and stitch removal. Bill modifier 24 on unrelated E/M visits and modifier 79 on unrelated procedures performed in that window.

03Do I need modifier LT or RT on every 27566 claim?

Best practice is yes. Most payers require laterality modifiers on unilateral knee procedures, and the matching ICD-10 code must specify the same side. A mismatch between the modifier and diagnosis laterality is a common edit trigger.

04When is modifier 50 appropriate for 27566?

Only when bilateral simultaneous open patellar dislocation reduction is performed — an uncommon clinical scenario. Bilateral traumatic patellar dislocation requiring open treatment at the same session would support modifier 50, but expect payer scrutiny and have documentation ready.

05How does 27566 differ from 27560 and 27562?

27560 and 27562 are closed treatment codes — no surgical incision. 27566 is the open reduction option, used when closed reduction fails or is clinically inappropriate, and may include partial or total patellectomy. The operative note must clearly indicate an open approach was performed.

06Can 27566 be billed with arthroscopy on the same knee at the same session?

Check the NCCI edits before billing both. If a separate, distinct procedure was performed through the arthroscope that is not integral to the open reduction, modifier 59 may apply — but only if documentation supports a truly independent service. Bundling rules for ipsilateral same-session knee procedures are strictly enforced.

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 dislocation chronicity (acute vs. recurrent), operative approach, laterality, whether patellectomy was performed and to what extent, and any failed closed reduction attempts — the specific elements that differentiate 27566 from closed treatment codes and recurrent-dislocation reconstruction codes. That prevents upcoding flags and mismatched CPT-ICD-10 denials before the claim leaves the practice.

See how Mira captures CPT 27566 documentation