M84.331A (Stress fracture, right ulna, initial encounter for fracture) compared with M84.332A (Stress fracture, left ulna, initial encounter for fracture), from the official CMS tabular data. M84.331A and M84.332A code the same condition on opposite sides.
Same condition; these differ only in which side is documented.
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: ICD-10-CM tabular list (laterality variant derived from the code title)
Same condition, opposite side. M84.331A and M84.332A 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.
| M84.331AStress fracture, right ulna, initial encounter for fracture | M84.332AStress fracture, left ulna, initial encounter for fracture | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) |
| Definition | Stress fracture, right ulna, initial encounter for fracture is a billable ICD-10-CM diagnosis code (M84.331A). | Stress fracture, left ulna, initial encounter for fracture is a billable ICD-10-CM diagnosis code (M84.332A). |
| 7th character | The appropriate 7th character is to be added to each code from subcategory M84.3: | The appropriate 7th character is to be added to each code from subcategory M84.3: |
| Use additional code | external cause code(s) to identify the cause of the stress fracture | external cause code(s) to identify the cause of the stress fracture |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources