ICD-10-CM 2027 diagnosis code
S21.45Open bite of back wall of thorax with penetration into thoracic cavity
S21.45 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.Short description: Open bite of back wall of thorax w penet thoracic cavity
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About S21.45
S21.45 is the ICD-10-CM diagnosis code for open bite of back wall of thorax with penetration into thoracic cavity. It belongs to category S21 (open wound of thorax), block S20-S29 (injuries to the thorax) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.
Within S21.4 (open wound of back wall of thorax with penetration into thoracic cavity), S21.45 is specifically for open bite of back wall of thorax with penetration into thoracic cavity. Related codes cover unspecified open wound of back wall of thorax with penetration into thoracic cavity (S21.40), laceration without foreign body of back wall of thorax with penetration into thoracic cavity (S21.41), laceration with foreign body of back wall of thorax with penetration into thoracic cavity (S21.42), puncture wound without foreign body of back wall of thorax with penetration into thoracic cavity (S21.43) and puncture wound with foreign body of back wall of thorax with penetration into thoracic cavity (S21.44).
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
Don't report S21.45 together with the conditions in its Excludes1 note: superficial bite of back wall of thorax (S20.47).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
The appropriate 7th character is to be added to each code from category S21
- S21.451Open bite of right back wall of thorax with penetration into thoracic cavity
- S21.452Open bite of left back wall of thorax with penetration into thoracic cavity
- S21.459Open bite of unspecified back wall of thorax with penetration into thoracic cavity
- Ainitial encounter
- Dsubsequent encounter
- Ssequela
Coding notes
- Bite of back wall of thorax NOS
- superficial bite of back wall of thorax (S20.47)
Notes that apply from higher levels
Instructions written at a parent level also apply to S21.45.
› From S21 Open wound of thorax
- traumatic amputation (partial) of thorax (S28.1)
Broader instructions also apply from S20-S29 Injuries to the thorax and Chapter 19: Injury, poisoning and certain other consequences of external causes.
Alphabetic index entries
1 entriesTerms in the official ICD-10-CM index that lead to S21.45.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about S21.45
Is S21.45 billable?
- No. S21.45 is a header code. Report one of its more specific subcodes instead.