S20.421ABillable
Blister (nonthermal) of right back wall of thorax, initial encounter
Short description: Blister (nonthermal) of right back wall of thorax, init
- Chapter
- 19. Injury, poisoning and certain other consequences of external causes
- Category
- S20
- Effective date
- October 1, 2026
Related codes in category S20
S20Superficial injury of thoraxS20.0Contusion of breastS20.00Contusion of breast, unspecified breastS20.00XAContusion of breast, unspecified breast, initial encounterYesS20.00XDContusion of breast, unspecified breast, subs encntrYesS20.00XSContusion of breast, unspecified breast, sequelaYesS20.01Contusion of right breastS20.01XAContusion of right breast, initial encounterYesS20.01XDContusion of right breast, subsequent encounterYesS20.01XSContusion of right breast, sequelaYesS20.02Contusion of left breastS20.02XAContusion of left breast, initial encounterYes
Frequently asked questions
What is ICD-10 code S20.421A?
S20.421A is an ICD-10-CM diagnosis code for Blister (nonthermal) of right back wall of thorax, initial encounter.
Is S20.421A a billable code?
Yes. S20.421A is billable and specific enough to be used on a claim.
What ICD-10-CM chapter is S20.421A in?
S20.421A falls under Chapter 19: Injury, poisoning and certain other consequences of external causes.
When did S20.421A become effective?
S20.421A has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to S20.421A?
S20.421A belongs to category S20, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.