ICD-10-CM 2027
ICD-10 code for resistant hypertension
From the official ICD-10-CM alphabetic index entry “Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) › resistant (apparent treatment) (treatment) (true)”. Page updated September 29, 2026.
About coding resistant hypertension
The ICD-10-CM code for resistant hypertension is I1A.0 (Resistant hypertension).
Code first specific type of existing hypertension, if known, such as: essential hypertension (I10) and secondary hypertension (I15.-).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 304 (Hypertension with MCC, relative weight 1.2011) and DRG 305 (Hypertension without MCC, relative weight 0.7581), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about resistant hypertension ICD-10 codes
What is the ICD-10 code for resistant hypertension?
- I1A.0 — Resistant hypertension.
Is I1A.0 billable?
- Yes. I1A.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I1A.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I1A.0 as a principal diagnosis.
Is I1A.0 a CC or MCC?
- No. I1A.0 is neither a CC nor an MCC under MS-DRG v44.0.