Avascular necrosis of the carpal lunate in patients aged 15 and older, classified under adult osteochondrosis of the carpal lunate and grouped within other osteochondropathies.
Verified May 8, 2026 · 4 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 9
- Region
- Wrist
Documentation tips
What should appear in the chart to support M93.1.
Source · Editorial brief grounded in 4 cited references ↓
- Document laterality explicitly (right or left wrist) in the clinical note — M93.1 has no laterality-specific subcode, but auditors and surgical coders need it for operative report accuracy.
- Record the Lichtman stage (I–IV) or equivalent staging language; this supports medical necessity for surgical intervention and distinguishes early from advanced disease.
- Note prior conservative treatment attempted (splinting, activity modification, NSAIDs) before surgical or interventional procedures — payors often require documented failure of conservative care.
- If MRI or plain radiographs were obtained, document findings: lunate signal change, collapse, fragmentation, carpal height ratio, or joint space narrowing — these support the diagnosis and the surgical plan.
- Confirm patient age is 15 or older before submitting M93.1; CMS enforces this age restriction at claim edit.
Related CPT procedures
Procedure codes commonly billed with M93.1. 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 M93.1 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- M93.1 has no laterality subcode — do not search for M93.11 or M93.12; they don't exist. Right, left, and bilateral all use the single code M93.1.
- Submitting M93.1 as the primary diagnosis supporting amniotic/placental-derived product injections will trigger a medical necessity denial per CMS LCD A59764 — choose a covered diagnosis or document a different primary condition if applicable.
- Do not use M93.1 for pediatric patients (under 15); the code carries a CMS age edit. Juvenile Kienböck's or lunate osteonecrosis in younger patients requires a different coding approach.
- Avoid conflating M93.1 with M87 series (osteonecrosis) codes — Kienböck's disease belongs under osteochondropathies (M93), not the primary/secondary osteonecrosis section, per the ICD-10-CM tabular hierarchy.
Clinical context
Source · Editorial summary grounded in 4 cited references ↓
M93.1 captures Kienböck's disease in adult patients (ages 15–124), a condition in which the lunate bone of the wrist undergoes progressive avascular necrosis, leading to collapse, carpal instability, and eventual wrist arthritis. The ICD-10-CM tabular includes 'adult osteochondrosis of carpal lunates' as an applicable synonym. Age restriction is enforced by CMS — this code cannot be submitted for pediatric patients under 15.
Use M93.1 whenever the treating provider documents Kienböck's disease, lunate avascular necrosis (adult), or adult lunate osteochondrosis. The code has no laterality subdivision — right, left, and bilateral lunate involvement all map to M93.1. This is a rare case in ICD-10-CM where a wrist-specific diagnosis carries no laterality distinction, so document side in the chart even though the code doesn't capture it.
M93.1 is listed by CMS as a diagnosis that does NOT support medical necessity for amniotic and placental-derived product (APDI) injections for musculoskeletal indications (LCD A59764). Payers will deny those procedures when M93.1 is the primary diagnosis. For surgical management — radial shortening osteotomy, proximal row carpectomy, wrist arthrodesis, or vascularized bone grafting — pair M93.1 with the appropriate CPT. DRG mapping falls under MS-DRG 553/554 (Bone diseases and arthropathies with/without MCC).
Inclusion & exclusion notes
Per the official ICD-10-CM Tabular List.
Source · CDC ICD-10-CM Official Tabular List · 2026
Includes
- Adult osteochondrosis of carpal lunates
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 4 cited references ↓
01Does M93.1 have separate codes for right and left wrist?
02Can M93.1 be used for a 12-year-old patient?
03Is M93.1 covered when billing for amniotic or placental-derived product injections?
04What CPT codes are typically paired with M93.1 for surgical management?
05Which DRGs does M93.1 map to?
06Should Kienböck's disease be coded with an M87 osteonecrosis code instead of M93.1?
07What imaging findings should be documented to support M93.1?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
Mira AI Scribe
The Mira AI Scribe captures laterality, Lichtman stage or radiographic findings (lunate collapse, signal change on MRI, carpal height loss), and prior conservative care from the encounter note — all of which prevent a vague operative report, support surgical medical necessity, and ensure the correct CPT is paired with M93.1 at claim submission.
See how Mira captures M93.1 documentation