I1A.0 Resistant hypertension

The ICD-10-CM code for Resistant hypertension is I1A.0 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

9: Diseases of the circulatory system (I00-I99)

Section

I10-I1A: Hypertensive diseases (I10-I1A)

Category I1A

2 codes (1 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to I1A.0:

• Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) › resistant (apparent treatment) (treatment) (true)

Inclusion Terms

• Apparent treatment resistant hypertension
• Treatment resistant hypertension
• True resistant hypertension

U.S. Hospital Utilization

• An estimated 6,535 U.S. inpatient stays in 2023 included I1A.0 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)