M66.342 (Spontaneous rupture of flexor tendons, left hand) compared with M66.349 (Spontaneous rupture of flexor tendons, unspecified hand), from the official CMS tabular data. M66.342 and M66.349 code the same condition on opposite sides. MedCoder-derived
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. M66.342 and M66.349 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.
| M66.342Spontaneous rupture of flexor tendons, left hand | M66.349Spontaneous rupture of flexor tendons, unspecified hand | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | M00-M99 — Diseases of the musculoskeletal system and connective tissue | M00-M99 — Diseases of the musculoskeletal system and connective tissue |
| Definition | Spontaneous rupture of flexor tendons, left hand is a billable ICD-10-CM diagnosis code (M66.342). | Spontaneous rupture of flexor tendons, unspecified hand is a billable ICD-10-CM diagnosis code (M66.349). |
| Includes | rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength | rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources