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M84.651K vs M84.653K

M84.651K (Pathological fracture in other disease, right femur, subsequent encounter for fracture with nonunion) compared with M84.653K (Pathological fracture in other disease, unspecified femur, subsequent encounter for fracture with nonunion), from the official CMS tabular data. M84.651K and M84.653K code the same condition on opposite sides. MedCoder-derived

Can these codes be reported together?

Review

Laterality relationship

M84.651K
Right
Pathological fracture in other disease, right femur, subsequent encounter for fracture with nonunion
M84.653K
Unspecified
Pathological fracture in other disease, unspecified femur, subsequent encounter for fracture with nonunion

What we found

Same condition, opposite side.M84.651K and M84.653K name the same condition on opposite sides of the body.

Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.

What to review

Report the side the documentation names. Where the code set provides a bilateral code and both sides are documented, use it instead of the pair.

Guide: Laterality codingCheck these on a claim

Why it matters

These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.

Source / rule

ICD-10-CM tabular list (laterality variant derived from the code title)

Side by side

M84.651KPathological fracture in other disease, right femur, subsequent encounter for fracture with nonunionM84.653KPathological fracture in other disease, unspecified femur, subsequent encounter for fracture with nonunion
Billing statusBillableBillable
ClassificationM00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99)M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99)
DefinitionPathological fracture in other disease, right femur, subsequent encounter for fracture with nonunion is a billable ICD-10-CM diagnosis code (M84.651K).Pathological fracture in other disease, unspecified femur, subsequent encounter for fracture with nonunion is a billable ICD-10-CM diagnosis code (M84.653K).
7th characterThe appropriate 7th character is to be added to each code from subcategory M84.6:The appropriate 7th character is to be added to each code from subcategory M84.6:
Excludes1
pathological fracture in osteoporosis (M80.-)
pathological fracture in osteoporosis (M80.-)
Excludes2
traumatic fracture of bone-see fracture, by site
traumatic fracture of bone-see fracture, by site
Code also
underlying condition
underlying condition

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

Derived from the official CMS ICD-10-CM tabular data (FY2026). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources