M85.661 Other cyst of bone, right lower leg

Billable ICD-10-CM code, FY2026.

Applies from M85 Other disorders of bone density and structure

Excludes1 (never code together)

• osteogenesis imperfecta (Q78.0)
• osteopetrosis (Q78.2)
• osteopoikilosis (Q78.8)
• polyostotic fibrous dysplasia (Q78.1)

Applies from M85.6 Other cyst of bone

Excludes1 (never code together)

• cyst of jaw NEC (M27.4)
• osteitis fibrosa cystica generalisata [von Recklinghausen's disease of bone] (E21.0)

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 733.29 Other bone cyst (approximate)

Nearby codes

• M85.65 Other cyst of bone, thigh
• M85.651 Other cyst of bone, right thigh
• M85.652 Other cyst of bone, left thigh
• M85.659 Other cyst of bone, unspecified thigh
• M85.66 Other cyst of bone, lower leg
• M85.661 Other cyst of bone, right lower leg (this code)
• M85.662 Other cyst of bone, left lower leg
• M85.669 Other cyst of bone, unspecified lower leg
• M85.67 Other cyst of bone, ankle and foot
• M85.671 Other cyst of bone, right ankle and foot
• M85.672 Other cyst of bone, left ankle and foot