M93.80 classifies other specified osteochondropathies affecting an unspecified anatomical site — used when the condition is definitively identified as a named osteochondropathy outside the common eponym categories but documentation lacks or omits laterality and precise joint location.

Documentation tips

What should appear in the chart to support M93.80.

Source · Editorial brief grounded in 4 cited references ↓

• Document the specific named osteochondropathy (e.g., Freiberg infraction, Köhler disease) to support the 'other specified' designation and avoid defaulting to unspecified M93.90.
• Record laterality explicitly — 'right' or 'left' — so the coder can assign the correct 6th character (1 or 2) and upgrade from M93.80 to a site-specific subcategory.
• Identify the joint or bone involved by anatomical name (e.g., second metatarsal head, tarsal navicular, distal femoral epiphysis) to enable site-specific code selection under M93.81–M93.89.
• Include imaging findings (plain film, MRI) that confirm osteochondropathy — fragmentation, sclerosis, epiphyseal flattening — to substantiate medical necessity for procedures billed alongside this diagnosis.
• Note skeletal maturity status or age, since many osteochondropathies are age- and growth-plate-dependent; this context supports clinical consistency during payer review.

Related CPT procedures

Procedure codes commonly billed with M93.80. 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 M93.80 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

• Defaulting to M93.80 when site and laterality are actually documented in the note — always check for a more specific M93.8x subcategory with the correct 5th character for site and 6th character for laterality before assigning M93.80.
• Confusing M93.80 with M93.90 (osteochondropathy, unspecified, of unspecified site) — M93.80 requires that the type of osteochondropathy is specifically named in the documentation; if the type itself is unspecified, M93.90 is correct.
• Assigning M93.80 for Osgood-Schlatter or Legg-Calvé-Perthes disease, which have dedicated codes in M91–M92 and should never be coded to M93.8x.
• Pairing M93.80 with a lateralized procedure code (e.g., a right-side arthroscopy) without also documenting why site is unspecified — this mismatch triggers medical necessity edits and potential audit flags.
• Using M93.80 on recurring encounters without updating to a site-specific code once imaging or specialist documentation confirms the anatomical location.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

Sibling codes

Other billable codes under M93.8 (laterality / anatomic variants).