Recurrent subluxation of the patella with laterality not documented or specified in the clinical record.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 6
- Region
- Knee
Documentation tips
What should appear in the chart to support M22.10.
Source · Editorial brief grounded in 5 cited references ↓
- Document the affected side by name (right or left) at every encounter — this single step upgrades M22.10 to the laterality-specific M22.11 or M22.12 and reduces denial risk.
- Record the number of subluxation episodes, mechanism, and whether each was spontaneous or activity-related to substantiate 'recurrent' versus a single acute event.
- Include physical exam findings that confirm patellar instability: positive apprehension sign, J-sign, lateral patellar tilt, or lateral patellar glide greater than 50%.
- Capture imaging findings that support the diagnosis: TT-TG distance on CT/MRI, trochlear dysplasia grade, patella alta ratio (Caton-Deschamps or Insall-Salvati), and lateral retinacular tightness.
- If conservative care has been attempted, document brace type and duration, physical therapy trials, and patient response — this is required for surgical authorization and DME coverage.
Related CPT procedures
Procedure codes commonly billed with M22.10. Linking the right diagnosis to the right procedure is what establishes medical necessity.
Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis
Common coding pitfalls
The recurring mistakes coders make with M22.10 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Using M22.10 when laterality is documented in the note — always assign M22.11 (right) or M22.12 (left); unspecified codes invite payer audits and downcoding.
- Confusing recurrent subluxation (M22.1x) with recurrent dislocation (M22.0x) — subluxation is an incomplete displacement; use the dislocation code only when the patella fully leaves the trochlear groove and requires reduction.
- Coding M22.10 for a first-time acute patellar subluxation — acute/traumatic events use S83.0x codes with the appropriate 7th-character encounter extension (A, D, or S); M22.1x codes require documentation of a recurrent pattern.
- Assuming M22.10 is acceptable for knee orthosis DME orders — CMS Policy Article A52465 lists laterality-specific patella codes for Group 2/3 orthosis coverage; unspecified codes may not satisfy medical necessity requirements.
- Failing to distinguish M22.10 from M22.2X9 (patellofemoral disorders, unspecified knee) — patellofemoral disorder is a broader category; if the specific diagnosis of recurrent subluxation is documented, M22.10 or its laterality-specific sibling is more precise.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M22.10 is the unspecified-laterality code for recurrent patellar subluxation — meaning the patella repeatedly slips partially out of the trochlear groove without fully dislocating. Use it only when the operative or clinical note genuinely does not identify the affected side. In practice, this should be rare: nearly every physical exam, imaging report, or surgical note will name the right or left knee. If laterality is documented, use M22.11 (right) or M22.12 (left) instead.
Recurrent subluxation is distinct from a single acute event (which would map to a traumatic S-code) and from complete recurrent dislocation (M22.00–M22.02). The ICD-10-CM Tabular List includes an 'Applicable To' note under the M22.1 parent: incomplete dislocation of patella maps here. Patients typically present with a history of multiple episodes of the kneecap shifting laterally, apprehension sign on exam, and often have associated trochlear dysplasia, patella alta, or increased TT-TG distance on imaging.
This code supports medical necessity for patellar stabilization bracing (per CMS LCD/Policy Article A52465, related M22.2X codes are explicitly listed for knee orthoses, though M22.10 itself is not — laterality-specific codes are preferred by payers). For surgical planning notes, physical therapy authorizations, and DME orders, always verify payer policy; unspecified laterality codes draw heightened scrutiny and are a common denial trigger.
Sibling codes
Other billable codes under M22.1 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01When should I use M22.10 instead of M22.11 or M22.12?
02What is the difference between M22.10 and M22.00 (recurrent dislocation)?
03Can I use M22.10 for a first-time patellar subluxation?
04Does M22.10 support medical necessity for a patellar stabilizing brace under Medicare?
05What CPT procedures are typically reported with M22.10 or its laterality-specific equivalents?
06Is M22.1 a billable code I can use for claims?
07Does the ICD-10-CM Tabular include any 'Applicable To' guidance under M22.1?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (FY2026, effective Oct 1, 2025)
- 02cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=52465
- 03icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M20-M25/M22-/M22.1
- 04outsourcestrategies.comhttps://www.outsourcestrategies.com/blog/patellofemoral-syndrome-coding-and-billing-guidelines/
- 05aapc.comhttps://www.aapc.com/codes/icd-10-codes/M22.1
Mira AI Scribe
Mira's AI scribe captures laterality, episode count, mechanism, apprehension sign findings, and imaging markers (TT-TG distance, trochlear grade, patella alta ratio) from the encounter note. That documentation locks in M22.11 or M22.12 instead of the unspecified M22.10, preventing payer denials tied to missing laterality and supporting surgical or DME authorization.
See how Mira captures M22.10 documentation