M81.6 identifies localized osteoporosis of the Lequesne type — a regionally confined reduction in bone mineral density without a current pathological fracture, distinct from systemic age-related or drug-induced osteoporosis.

Documentation tips

What should appear in the chart to support M81.6.

Source · Editorial brief grounded in 4 cited references ↓

• Specify the affected joint or anatomic region in the note (e.g., periarticular osteoporosis of the right hip) — M81.6 carries no laterality digit, so the site must live in the clinical narrative.
• Document the absence of a current pathological fracture explicitly; if a fracture is present, M81.6 is excluded and an M80 code with 7th character is required.
• Record the imaging basis for the diagnosis: plain radiograph findings (periarticular lucency, cortical thinning) or DEXA T-score with the specific region scanned.
• Note the suspected etiology of localized bone loss (disuse, post-immobilization, periarticular inflammatory change) to distinguish M81.6 from systemic osteoporosis codes and from Sudeck's atrophy (M89.0).
• If a major osseous defect is identified, add M89.7- as an additional code per the M81 parent-code instruction; document the defect site to support that code.
• If the patient has a prior healed osteoporotic fracture, document it and append Z87.310 per the Use Additional Code instruction under M81.

Related CPT procedures

Procedure codes commonly billed with M81.6. 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 M81.6 and adjacent codes.

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

• Assigning M81.6 when a current pathological fracture is present — the M81 series is entirely excluded in that scenario; use M80 with the correct site, laterality, and 7th-character encounter type.
• Confusing M81.6 with M89.0 (Sudeck's atrophy): the M81 tabular explicitly excludes Sudeck's atrophy; if reflex sympathetic dystrophy or complex regional pain syndrome is the driver of focal bone loss, M89.0 is the correct code.
• Defaulting to M81.0 (age-related osteoporosis) when the provider documents localized or periarticular bone loss — M81.6 is the specific code and should be used when the clinical record supports it.
• Omitting secondary codes required by the M81 parent-code instructions: M89.7- for major osseous defect and Z87.310 for personal history of healed osteoporotic fracture are additive, not optional, when those conditions exist.
• Treating M81.6 as a site-specific code — it has no 5th or 6th character for anatomic location or laterality; attempting to append extra digits will render the code invalid.

Clinical context

Source · Editorial summary grounded in 4 cited references ↓

Inclusion & exclusion notes

Per the official ICD-10-CM Tabular List.

Source · CDC ICD-10-CM Official Tabular List · 2026

Sibling codes

Other billable codes under M81 (laterality / anatomic variants).