M84.559K Pathological fracture in neoplastic disease, hip, unspecified, subsequent encounter for fracture with nonunion

Billable ICD-10-CM code, FY2026.

Built from M84.559 with 7th character K (subsequent encounter for fracture with nonunion).

Applies from M84 Disorder of continuity of bone

Excludes2 (not included here)

• traumatic fracture of bone-see fracture, by site

Applies from M84.5 Pathological fracture in neoplastic disease

Code also

• underlying neoplasm

7th character note

• The appropriate 7th character is to be added to each code from subcategory M84.5:

7th character required

• A — initial encounter for fracture
• D — subsequent encounter for fracture with routine healing
• G — subsequent encounter for fracture with delayed healing
• K — subsequent encounter for fracture with nonunion
• P — subsequent encounter for fracture with malunion
• S — sequela

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 M84.559K

Back-references to M84.5

• Type 1 Excludes: M84.4 Pathological fracture, not elsewhere classified ("pathological fracture in neoplastic disease (M84.5-)")

Diagnosis Index entries for M84.559K

• Fracture, pathological (pathologic) › due to › neoplastic disease NEC › hip

Nearby codes

• M84.553S Pathological fracture in neoplastic disease, unspecified femur, sequela
• M84.559 Pathological fracture in neoplastic disease, hip, unspecified
• M84.559A Pathological fracture in neoplastic disease, hip, unspecified, initial encounter for fracture
• M84.559D Pathological fracture in neoplastic disease, hip, unspecified, subsequent encounter for fracture with routine healing
• M84.559G Pathological fracture in neoplastic disease, hip, unspecified, subsequent encounter for fracture with delayed healing
• M84.559K Pathological fracture in neoplastic disease, hip, unspecified, subsequent encounter for fracture with nonunion (this code)
• M84.559P Pathological fracture in neoplastic disease, hip, unspecified, subsequent encounter for fracture with malunion
• M84.559S Pathological fracture in neoplastic disease, hip, unspecified, sequela
• M84.56 Pathological fracture in neoplastic disease, tibia and fibula
• M84.561 Pathological fracture in neoplastic disease, right tibia
• M84.561A Pathological fracture in neoplastic disease, right tibia, initial encounter for fracture