R91Header code — not billable
Abnormal findings on diagnostic imaging of lung
- Chapter
- 18. Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
- Category
- R91
- Effective date
- October 1, 2026
Related codes in category R91
Frequently asked questions
What is ICD-10 code R91?
R91 is an ICD-10-CM diagnosis code for Abnormal findings on diagnostic imaging of lung.
Is R91 a billable code?
No. R91 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 R91 in?
R91 falls under Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified.
When did R91 become effective?
R91 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to R91?
R91 belongs to category R91, which includes 2 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.