ICD-10-CM 2027 diagnosis code

R91Abnormal findings on diagnostic imaging of lung

Not billable — use a more specific code

R91 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About R91

R91 is the ICD-10-CM diagnosis code for abnormal findings on diagnostic imaging of lung. It belongs to block R90-R94 (abnormal findings on diagnostic imaging and in function studies, without diagnosis) and chapter 18 (symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: R91.1 (nodule) and R91.8 (field).

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

Specific codes under R91

Notes that apply from higher levels

Instructions written at a parent level also apply to R91.

Broader instructions also apply from R90-R94 Abnormal findings on diagnostic imaging and in function studies, without diagnosis and Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified.

Code history

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2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about R91

Is R91 billable?: No. R91 is a header code. Report one of its more specific subcodes instead.