S00.421ABillable
Blister (nonthermal) of right ear, initial encounter
- Chapter
- 19. Injury, poisoning and certain other consequences of external causes
- Category
- S00
- Effective date
- October 1, 2026
Related codes in category S00
S00Superficial injury of headS00.0Superficial injury of scalpS00.00Unspecified superficial injury of scalpS00.00XAUnspecified superficial injury of scalp, initial encounterYesS00.00XDUnspecified superficial injury of scalp, subs encntrYesS00.00XSUnspecified superficial injury of scalp, sequelaYesS00.01Abrasion of scalpS00.01XAAbrasion of scalp, initial encounterYesS00.01XDAbrasion of scalp, subsequent encounterYesS00.01XSAbrasion of scalp, sequelaYesS00.02Blister (nonthermal) of scalpS00.02XABlister (nonthermal) of scalp, initial encounterYes
Frequently asked questions
What is ICD-10 code S00.421A?
S00.421A is an ICD-10-CM diagnosis code for Blister (nonthermal) of right ear, initial encounter.
Is S00.421A a billable code?
Yes. S00.421A is billable and specific enough to be used on a claim.
What ICD-10-CM chapter is S00.421A in?
S00.421A falls under Chapter 19: Injury, poisoning and certain other consequences of external causes.
When did S00.421A become effective?
S00.421A has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to S00.421A?
S00.421A belongs to category S00, 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.