I15 Secondary hypertension

The ICD-10-CM code for Secondary hypertension is I15 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter

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

Section

I10-I1A: Hypertensive diseases (I10-I1A)

Category I15

6 codes (5 billable)

FY2026 Status

Stable since FY2024

Official Coding Guidelines

Code separately if documented unrelated; assign I10 or I15; sequence per encounter

The same heart conditions (I50.-, I51.4-I51.7, I51.89, I51.9) with hypertension are coded separately if the provider has documented they are unrelated to the hypertension. The applicable hypertension code I10, Essential (primary) hypertension, or a code from category I15, Secondary hypertension, should be assigned. Sequence according to the circumstances of the admission/encounter.

Use H35.0 with I10-I15 to include systemic HTN; sequencing per reason

Subcategory H35.0, Background retinopathy and retinal vascular changes, should be used along with a code from categories I10 - I15, in the Hypertensive diseases section, to include the systemic hypertension. The sequencing is based on the reason for the encounter.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool