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S66.504A vs S66.505A

S66.504A (Unspecified injury of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level, initial encounter) compared with S66.505A (Unspecified injury of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level, initial encounter), from the official CMS tabular data. S66.504A and S66.505A code the same condition on opposite sides. MedCoder-derived

Relationship

Review

Laterality relationship

S66.504A
Right
Unspecified injury of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level, initial encounter
S66.505A
Left
Unspecified injury of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level, initial encounter

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)

Can these codes be reported together?

Same condition, opposite side. S66.504A and S66.505A 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.

Side by side

S66.504AUnspecified injury of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level, initial encounterS66.505AUnspecified injury of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level, initial encounter
Billing statusBillableBillable
ClassificationS00-T88 — Injury, poisoning and certain other consequences of external causesS00-T88 — Injury, poisoning and certain other consequences of external causes
DefinitionUnspecified injury of intrinsic muscle, fascia and tendon of right ring finger at wrist and hand level, initial encounter is a billable ICD-10-CM diagnosis code (S66.504A).Unspecified injury of intrinsic muscle, fascia and tendon of left ring finger at wrist and hand level, initial encounter is a billable ICD-10-CM diagnosis code (S66.505A).
7th characterThe appropriate 7th character is to be added to each code from category S66The appropriate 7th character is to be added to each code from category S66

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources