S20.344A (External constriction of middle front wall of thorax, initial encounter) compared with S20.344D (External constriction of middle front wall of thorax, subsequent encounter), from the official CMS tabular data. S20.344A and S20.344D code the same injury at a different phase of treatment.
Same underlying diagnosis, different encounter phase.
The 7th character records the phase of care for the encounter being coded, so a single encounter takes one of these characters, not several. Review whether both phases belong on the same episode of care.
Source: ICD-10-CM Official Guidelines, Section I.C.19.a
Same injury, other encounter phase. S20.344A and S20.344D 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.
| S20.344AExternal constriction of middle front wall of thorax, initial encounter | S20.344DExternal constriction of middle front wall of thorax, subsequent encounter | |
|---|---|---|
| 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 | External constriction of middle front wall of thorax, initial encounter is a billable ICD-10-CM diagnosis code (S20.344A). | External constriction of middle front wall of thorax, subsequent encounter is a billable ICD-10-CM diagnosis code (S20.344D). |
| 7th character | The appropriate 7th character is to be added to each code from category S20 | The appropriate 7th character is to be added to each code from category S20 |
| 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