M13.1Header code — not billable
Monoarthritis, not elsewhere classified
- Chapter
- 13. Diseases of the musculoskeletal system and connective tissue
- Category
- M13
- Effective date
- October 1, 2026
Related codes in category M13
M13Other arthritisM13.0Polyarthritis, unspecifiedYesM13.10Monoarthritis, not elsewhere classified, unspecified siteYesM13.11Monoarthritis, not elsewhere classified, shoulderM13.111Monoarthritis, not elsewhere classified, right shoulderYesM13.112Monoarthritis, not elsewhere classified, left shoulderYesM13.119Monoarthritis, not elsewhere classified, unsp shoulderYesM13.12Monoarthritis, not elsewhere classified, elbowM13.121Monoarthritis, not elsewhere classified, right elbowYesM13.122Monoarthritis, not elsewhere classified, left elbowYesM13.129Monoarthritis, not elsewhere classified, unspecified elbowYesM13.13Monoarthritis, not elsewhere classified, wrist
Frequently asked questions
What is ICD-10 code M13.1?
M13.1 is an ICD-10-CM diagnosis code for Monoarthritis, not elsewhere classified.
Is M13.1 a billable code?
No. M13.1 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is M13.1 in?
M13.1 falls under Chapter 13: Diseases of the musculoskeletal system and connective tissue.
When did M13.1 become effective?
M13.1 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to M13.1?
M13.1 belongs to category M13, 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.