Skip to content
Dx

ICD-10-CM 2027

ICD-10 code for interscapular region blister

S20.429

Blister (nonthermal) of unspecified back wall of thorax

Header — needs a more specific code

From the official ICD-10-CM alphabetic index entry “Blister (nonthermal) › interscapular region”. Page updated September 29, 2026.

About coding interscapular region blister

The ICD-10-CM code for interscapular region blister is S20.429 (Blister (nonthermal) of unspecified back wall of thorax).

Within S20.42, choose S20.429 (unspecified back wall of thorax) only when documentation doesn't support a more specific option: right back wall of thorax (S20.421) and left back wall of thorax (S20.422).

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.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Common questions about interscapular region blister ICD-10 codes

What is the ICD-10 code for interscapular region blister?

S20.429 — Blister (nonthermal) of unspecified back wall of thorax (a header code; report a more specific subcode).

Is S20.429 billable?

No. S20.429 is a header code. Report one of its more specific subcodes instead.