Is S21.251D a billable ICD-10-CM code?

Yes. S21.251D is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does S21.251D 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 S21.251D?

S21.251D 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 S21.251D (S21.25, S21) and apply to it just the same.

S21.251D

S21.251D — Open bite of right back wall of thorax without penetration into thoracic cavity, subsequent encounter

Billable / specific codeICD-10-CMPOA exemptright

S21.251D is a billable, specific ICD-10-CM code for open bite of right back wall of thorax without penetration into thoracic cavity, subsequent encounter. It is valid for submission on a claim.

7th character "D" — subsequent encounter

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 S21.251D

These are not written on S21.251D, but they bind it: a note on a category applies to every code beneath it. Billing S21.251D with anything listed here is a denial.

Written on S21.25 — Open bite of back wall of thorax without penetration into thoracic cavity

superficial bite of back wall of thorax (S20.47)

Written on S21 — Open wound of thorax

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

Risk adjustment

S21.251D 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

S21.251D is named in 8 Medicare coverage policies — 8 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A53058Billing and Coding: Home Health Physical Therapy
A53065Billing and Coding: Outpatient Physical Therapy
A54767Billing and Coding: Medicare Preventive Coverage for Certain Vaccines
A56421Billing and Coding: CT of the Abdomen and Pelvis

Code history

S21.251D 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 S21.251. If S21.251D is not quite right, the correct code is usually one of these.

Questions about S21.251D

Is S21.251D a billable ICD-10-CM code?: Yes. S21.251D is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does S21.251D 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 S21.251D?: S21.251D 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 S21.251D (S21.25, S21) and apply to it just the same.