M84.639K Pathological fracture in other disease, unspecified ulna and radius, subsequent encounter for fracture with nonunion

Billable ICD-10-CM code, FY2026.

Built from M84.639 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 M84.6 Pathological fracture in other disease

Excludes1 (never code together)

• pathological fracture in osteoporosis (M80.-)

Code also

• underlying condition

7th character note

• The appropriate 7th character is to be added to each code from subcategory M84.6:

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 M84.639K

Back-references to M84.6

• Type 1 Excludes: M84.4 Pathological fracture, not elsewhere classified ("pathological fracture in other disease (M84.6-)")

Nearby codes

• M84.634S Pathological fracture in other disease, left radius, sequela
• M84.639 Pathological fracture in other disease, unspecified ulna and radius
• M84.639A Pathological fracture in other disease, unspecified ulna and radius, initial encounter for fracture
• M84.639D Pathological fracture in other disease, unspecified ulna and radius, subsequent encounter for fracture with routine healing
• M84.639G Pathological fracture in other disease, unspecified ulna and radius, subsequent encounter for fracture with delayed healing
• M84.639K Pathological fracture in other disease, unspecified ulna and radius, subsequent encounter for fracture with nonunion (this code)
• M84.639P Pathological fracture in other disease, unspecified ulna and radius, subsequent encounter for fracture with malunion
• M84.639S Pathological fracture in other disease, unspecified ulna and radius, sequela
• M84.64 Pathological fracture in other disease, hand
• M84.641 Pathological fracture in other disease, right hand
• M84.641A Pathological fracture in other disease, right hand, initial encounter for fracture