ICD-10-CM 2027 diagnosis code

I15Secondary hypertension

Not billable — use a more specific code

I15 is a header code, so it can't be reported by itself. Choose one of the 5 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 I15

I15 is the ICD-10-CM diagnosis code for secondary hypertension. It belongs to block I10-I1A (hypertensive diseases) and chapter 9 (diseases of the circulatory system). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: I15.0 (hypertension), I15.1 (disorders), I15.2 (disorders), I15.8 (hypertension) and I15.9 (unspecified).

Don't report I15 together with the conditions in its Excludes1 note: postprocedural hypertension (I97.3).

The conditions in its Excludes2 note aren't part of I15, but may be coded alongside it if the patient has both: secondary hypertension involving vessels of brain (I60-I69) and secondary hypertension involving vessels of eye (H35.0-).

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 I15

Coding notes

Excludes1Not coded here — never report together with this code

postprocedural hypertension (I97.3)

Excludes2Not included here — may be reported together if both conditions exist

secondary hypertension involving vessels of brain (I60-I69)
secondary hypertension involving vessels of eye (H35.0-)

Code alsoTwo codes may be needed; sequencing depends on circumstances

underlying condition

Notes that apply from higher levels

Instructions written at a parent level also apply to I15.

Broader instructions also apply from I10-I1A Hypertensive diseases and Chapter 9: Diseases of the circulatory system.

Codes whose notes reference I15

I12Excludes1
I16Code also
I1A.0Code first
O10.4Use additional code

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

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

Common questions about I15

Is I15 billable?: No. I15 is a header code. Report one of its more specific subcodes instead.