DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

R21 diagnosis code · Billable category · FY2027

R21 Rash and other nonspecific skin eruption

  • Billable
  • Not CC/MCC
  • POA reported

R21 ICD-10 code: a billable diagnosis code in FY2027; the category has no subdivisions.

ICD-10 code by name

What is the ICD-10 code for rash?
Rash ICD-10 code: R21 Rash and other nonspecific skin eruption. Alphabetic Index: Rash (toxic) → R21. Search ICD-10 for rash

Where it sits

  1. Chapter 18 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
  2. R20-R23 Symptoms and signs involving the skin and subcutaneous tissue (R20-R23)
  3. R21 Rash and other nonspecific skin eruption
CC / MCC
Neither
MS-DRG
606-607
HCC V28
–
POA
Reported
Code Editor
–
Index entries
4

Instructions

At R21

Includes

  • rash NOS

Excludes1

  • specified type of rash- code to condition
  • vesicular eruption (R23.8) R23.8

Notes that also apply

Block R20-R23 instructions (Excludes2 1): printed on the block page.

Chapter 18 instructions (Notes 9, Excludes2 4): printed on the chapter 18 page.

Index entries

  • Rash (toxic) → R21
  • Eruptionskin (nonspecific) → R21
  • Rash (toxic)rose → R21
  • Roserash → R21

NCHS Alphabetic Index. Index first, then the Tabular List.

Medicare grouping and edits

CMS files for R21
CC / MCCNeither
Appendix BMDC 09 Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast, MS-DRG 606-607 (Minor Skin Disorders with MCC…)
Code Editor–
POAReported
HCC V28–

CMS: MS-DRG v44 (Appendix B, C), MCE v44, POA list FY2027, 2027 Initial ICD-10-CM Mappings. What the rows mean.

Hierarchy