Is S21.359S a billable ICD-10-CM code?

Yes. S21.359S is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does S21.359S sit in the tabular list?

Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the thorax (S20-S29).

What cannot be coded together with S21.359S?

S21.359S carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above S21.359S (S21.35, S21) and apply to it just the same.

S21.359S

S21.359S — Open bite of unspecified front wall of thorax with penetration into thoracic cavity, sequela

Billable / specific codeICD-10-CMPOA exempt

S21.359S is a billable, specific ICD-10-CM code for open bite of unspecified front wall of thorax with penetration into thoracic cavity, sequela. It is valid for submission on a claim.

7th character "S" — sequela

The appropriate 7th character is to be added to each code from category S21

A: initial encounter
D: subsequent encounter
S: sequela

Excludes1 inherited from the categories above S21.359S

These are not written on S21.359S, but they bind it: a note on a category applies to every code beneath it. Billing S21.359S with anything listed here is a denial.

Written on S21.35 — Open bite of front wall of thorax with penetration into thoracic cavity

superficial bite of front wall of thorax (S20.37)

Written on S21 — Open wound of thorax

traumatic amputation (partial) of thorax (S28.1)

Risk adjustment

S21.359S does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

S21.359S is named in 1 Medicare coverage policy — 1 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A56717Billing and Coding: Respiratory Therapy (Respiratory Care)

Code history

S21.359S has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share S21.359. If S21.359S is not quite right, the correct code is usually one of these.

Questions about S21.359S

Is S21.359S a billable ICD-10-CM code?: Yes. S21.359S is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does S21.359S sit in the tabular list?: Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the thorax (S20-S29).
What cannot be coded together with S21.359S?: S21.359S carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above S21.359S (S21.35, S21) and apply to it just the same.