S21.042A vs S21.042S
S21.042A (Puncture wound with foreign body of left breast, initial encounter) compared with S21.042S (Puncture wound with foreign body of left breast, sequela), from the official CMS tabular data. S21.042A and S21.042S code the same injury at a different phase of treatment.
Can these codes be reported together?
Same injury, other encounter phase. S21.042A and S21.042S code the same injury at a different phase of treatment, set by the 7th character.
The 7th character records the type of care given at the encounter being coded (ICD-10-CM Official Guidelines, Section I.C.19.a), so one encounter takes one of these, not both.
Side by side
| S21.042APuncture wound with foreign body of left breast, initial encounter | S21.042SPuncture wound with foreign body of left breast, sequela | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Puncture wound with foreign body of left breast, initial encounter is a billable ICD-10-CM diagnosis code (S21.042A). | Puncture wound with foreign body of left breast, sequela is a billable ICD-10-CM diagnosis code (S21.042S). |
| 7th character | The appropriate 7th character is to be added to each code from category S21 | The appropriate 7th character is to be added to each code from category S21 |
| Includes | injuries of breast injuries of chest (wall) injuries of interscapular area | injuries of breast injuries of chest (wall) injuries of interscapular area |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources