S21.159A vs S21.159S
S21.159A (Open bite of unspecified front wall of thorax without penetration into thoracic cavity, initial encounter) compared with S21.159S (Open bite of unspecified front wall of thorax without penetration into thoracic cavity, sequela), from the official CMS tabular data. S21.159A and S21.159S code the same injury at a different phase of treatment.
Can these codes be reported together?
Same injury, other encounter phase. S21.159A and S21.159S 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
| S21.159AOpen bite of unspecified front wall of thorax without penetration into thoracic cavity, initial encounter | S21.159SOpen bite of unspecified front wall of thorax without penetration into thoracic cavity, 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 | Open bite of unspecified front wall of thorax without penetration into thoracic cavity, initial encounter is a billable ICD-10-CM diagnosis code (S21.159A). | Open bite of unspecified front wall of thorax without penetration into thoracic cavity, sequela is a billable ICD-10-CM diagnosis code (S21.159S). |
| 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