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S66.021A vs S66.022A

S66.021A (Laceration of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, initial encounter) compared with S66.022A (Laceration of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, initial encounter), from the official CMS tabular data. S66.021A and S66.022A code the same condition on opposite sides. MedCoder-derived

Relationship

Review

Laterality relationship

S66.021A
Right
Laceration of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, initial encounter
S66.022A
Left
Laceration of long flexor muscle, fascia and tendon of left thumb 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. S66.021A and S66.022A 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

S66.021ALaceration of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, initial encounterS66.022ALaceration of long flexor muscle, fascia and tendon of left thumb 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
DefinitionLaceration of long flexor muscle, fascia and tendon of right thumb at wrist and hand level, initial encounter is a billable ICD-10-CM diagnosis code (S66.021A).Laceration of long flexor muscle, fascia and tendon of left thumb at wrist and hand level, initial encounter is a billable ICD-10-CM diagnosis code (S66.022A).
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