Idiopathic aseptic necrosis of bone affecting multiple skeletal sites simultaneously, with no identifiable traumatic or drug-related cause.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 8
- Region
- Multi-region
Documentation tips
What should appear in the chart to support M87.09.
Source · Editorial brief grounded in 5 cited references ↓
- Explicitly document 'idiopathic' etiology — the note must state no known cause (no corticosteroid use, no alcohol use, no prior trauma) to justify M87.09 over M87.1x or M87.2x.
- List every affected bone by name and side (e.g., right femoral head, left humeral head) so the multi-site designation is clinically defensible.
- Record MRI findings supporting osteonecrosis at each site — subchondral collapse, bone marrow edema, or crescent sign — correlated to the specific bone affected.
- Note the Ficat-Arlet or ARCO staging (or equivalent) for each involved site to support surgical authorization and level-of-service documentation.
- If a major osseous defect is present at any site, co-code M89.7- per the M87 'Use Additional' instruction.
- Document the absence of corticosteroid or immunosuppressant therapy in the medication and history review to block a potential M87.1x recode on audit.
Related CPT procedures
Procedure codes commonly billed with M87.09. 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 M87.09 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Assigning M87.09 when osteonecrosis is corticosteroid- or alcohol-related — those cases require M87.1x; 'idiopathic' means no identified cause.
- Using M87.0 (the non-billable parent) instead of M87.09 for multi-site idiopathic AVN — M87.0 is not valid for claim submission.
- Stacking multiple single-site M87.0x codes instead of M87.09 when the tabular provides a 'multiple sites' code; the Official Guidelines instruct use of the multiple-sites code when available.
- Documenting only the joint (e.g., 'bilateral hip AVN') without naming the bone (femoral head) — per Official Guidelines, Chapter 13 site designation for M87 is the bone, not the joint.
- Omitting the M89.7- add-on code when imaging documents a major osseous defect at any affected site — this is a required 'Use Additional' instruction at the M87 category level.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M87.09 is the correct code when a patient presents with confirmed idiopathic avascular necrosis (AVN) involving two or more distinct bone sites and the etiology is documented as unknown — no history of corticosteroid use, alcohol use, trauma, or other secondary cause. The ICD-10-CM tabular structure under M87.0 provides site-specific codes (shoulder, humerus, radius/ulna/carpus, femur, etc.) as the first choice; M87.09 applies only when multiple of those sites are simultaneously involved in a single idiopathic presentation.
The 'idiopathic' qualifier is load-bearing. If osteonecrosis is drug-induced (e.g., corticosteroids), code to M87.1x instead; if post-traumatic, use M87.2x. Per the M87 category note, add a code for major osseous defect (M89.7-) when applicable. Because the site designation in M87 refers to the bone affected — not the adjacent joint — document the specific bones involved (e.g., bilateral femoral heads plus right humeral head), not just the joints.
For Chapter 13 multi-site conditions, ICD-10-CM Official Guidelines instruct coders to use a 'multiple sites' code when one is available rather than stacking individual site codes — M87.09 is that code for idiopathic AVN. Confirm the encounter note explicitly rules out steroid exposure, alcohol use, and trauma before assigning M87.09 over a more etiologically specific subcategory.
Sibling codes
Other billable codes under M87.0 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01When should I use M87.09 instead of individual site-specific M87.0x codes?
02Can I use M87.09 if the patient is on long-term corticosteroids?
03Does M87.09 require a 7th character?
04What is the correct site designation for AVN — the bone or the joint?
05Is there an additional code required when a major osseous defect is present?
06What imaging findings should the note include to support M87.09?
07How does M87.09 differ from M87.9 (Osteonecrosis, unspecified)?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
- 02cms.govhttps://www.cms.gov/files/document/fy-2025-icd-10-cm-coding-guidelines.pdf
- 03icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M86-M90/M87-/M87.09
- 04icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M86-M90/M87-/M87.0
- 05aapc.comhttps://www.aapc.com/codes/icd-10-codes/M87.09
Mira AI Scribe
Mira AI Scribe captures each affected bone by name and laterality, documents the absence of corticosteroid use, alcohol use, and trauma in the history, and records MRI or imaging findings (subchondral collapse, crescent sign, marrow edema) at every involved site. That documentation prevents downcoding to the non-billable M87.0 parent, blocks reclassification to drug-induced M87.1x on audit, and satisfies the Chapter 13 requirement to identify the bone rather than the joint.
See how Mira captures M87.09 documentation