M87.00 Idiopathic aseptic necrosis of unspecified bone

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from M87 Osteonecrosis

Includes

• avascular necrosis of bone

Excludes1 (never code together)

• juvenile osteonecrosis (M91-M92)
• osteochondropathies (M90-M93)

Use additional code

• code to identify major osseous defect, if applicable (M89.7-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 92 — Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis
• CMS-HCC V22: HCC 39 — Bone/Joint/Muscle Infections/Necrosis
• RxHCC V08: HCC 80 — Aseptic Necrosis of Bone
• ESRD V24: HCC 39

MS-DRG index

Defines the logic of DRG(s) 553-554 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 733.40 Aseptic necrosis of bone, site unspecified (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Unspecified code (laterality): Unspecified codes for which a more specific code identifying laterality (right, left, bilateral) exists within the same code family.

Code annotations containing back-references to M87.00

Back-references to M87

• Code First: M89.7 Major osseous defect ("aseptic necrosis of bone (M87.-)")
• Code First: M89.7 Major osseous defect ("osteonecrosis (M87.-)")

Diagnosis Index entries for M87.00

• Necrosis, necrotic (ischemic) › bone › aseptic or avascular › idiopathic
• Osteonecrosis › idiopathic aseptic

Nearby codes

• M87 Osteonecrosis
• M87.0 Idiopathic aseptic necrosis of bone
• M87.00 Idiopathic aseptic necrosis of unspecified bone (this code)
• M87.01 Idiopathic aseptic necrosis of shoulder
• M87.011 Idiopathic aseptic necrosis of right shoulder
• M87.012 Idiopathic aseptic necrosis of left shoulder
• M87.019 Idiopathic aseptic necrosis of unspecified shoulder
• M87.02 Idiopathic aseptic necrosis of humerus