M84.331A Stress fracture, right ulna, initial encounter for fracture

Billable ICD-10-CM code, FY2026.

Built from M84.331 with 7th character A (initial encounter for fracture).

Applies from M84 Disorder of continuity of bone

Excludes2 (not included here)

• traumatic fracture of bone-see fracture, by site

Applies from M84.3 Stress fracture

Applicable to

• Fatigue fracture
• March fracture
• Stress fracture NOS
• Stress reaction

Excludes1 (never code together)

• pathological fracture NOS (M84.4.-)
• pathological fracture due to osteoporosis (M80.-)
• traumatic fracture (S12.-, S22.-, S32.-, S42.-, S52.-, S62.-, S72.-, S82.-, S92.-)

Excludes2 (not included here)

• personal history of (healed) stress (fatigue) fracture (Z87.312)
• stress fracture of vertebra (M48.4-)

Use additional code

• external cause code(s) to identify the cause of the stress fracture

7th character note

• The appropriate 7th character is to be added to each code from subcategory M84.3:

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

Code annotations containing back-references to M84.331A

Back-references to M84.3

• Type 1 Excludes: M84.4 Pathological fracture, not elsewhere classified ("stress fracture (M84.3-)")

Nearby codes

• M84.329K Stress fracture, unspecified humerus, subsequent encounter for fracture with nonunion
• M84.329P Stress fracture, unspecified humerus, subsequent encounter for fracture with malunion
• M84.329S Stress fracture, unspecified humerus, sequela
• M84.33 Stress fracture, ulna and radius
• M84.331 Stress fracture, right ulna
• M84.331A Stress fracture, right ulna, initial encounter for fracture (this code)
• M84.331D Stress fracture, right ulna, subsequent encounter for fracture with routine healing
• M84.331G Stress fracture, right ulna, subsequent encounter for fracture with delayed healing
• M84.331K Stress fracture, right ulna, subsequent encounter for fracture with nonunion
• M84.331P Stress fracture, right ulna, subsequent encounter for fracture with malunion
• M84.331S Stress fracture, right ulna, sequela