ICD-10-CM 2027
ICD-10 code for Prothrombin time PT abnormal
From the official ICD-10-CM alphabetic index entry “Abnormal, abnormality, abnormalities › prothrombin time (PT)”. Page updated September 29, 2026.
About coding Prothrombin time PT abnormal
The ICD-10-CM code for Prothrombin time PT abnormal is R79.1 (Abnormal coagulation profile).
Within R79 (other abnormal findings of blood chemistry), R79.1 is specifically for abnormal coagulation profile. Related codes cover abnormal level of blood mineral (R79.0), other specified abnormal findings of blood chemistry (R79.8) and abnormal finding of blood chemistry, unspecified (R79.9).
Don't report R79.1 together with the conditions in its Excludes1 note: coagulation defects (D68.-).
The conditions in its Excludes2 note aren't part of R79.1, but may be coded alongside it if the patient has both: abnormality of fluid, electrolyte or acid-base balance (E86-E87).
Don't confuse with (Excludes1 for R79.1)
- coagulation defects (D68.-)
Common questions about Prothrombin time PT abnormal ICD-10 codes
What is the ICD-10 code for Prothrombin time PT abnormal?
- R79.1 — Abnormal coagulation profile.
Is R79.1 billable?
- Yes. R79.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R79.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R79.1 as a principal diagnosis.
Is R79.1 a CC or MCC?
- No. R79.1 is neither a CC nor an MCC under MS-DRG v44.0.