Is ICD-10-CM code I1A billable?

No, I1A (Other hypertension) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code I1A belong to?

I1A belongs to Chapter 9 of the ICD-10-CM tabular list: I00–I99 (Diseases of the Circulatory System).

I1ANot billable, use a more specific code below

Other hypertension

In Hypertensive diseases (I10-I1A), chapter 9: Diseases of the Circulatory System

1 billable code under I1A: none are a CC or MCC; none map to an HCC.

Instructional notes

Also applies, from Hypertensive diseases (I10-I1A)

These notes sit on I10-I1A and apply to every code under it, including I1A.

Excludes1: not coded here, use a different code

neonatal hypertension (P29.2)
primary pulmonary hypertension (I27.0)

Excludes2: not included here, code separately if applicable

hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)

Use additional code: add a second code for this, listed after this one

code to identify:
exposure to environmental tobacco smoke (Z77.22)
history of tobacco dependence (Z87.891)
occupational exposure to environmental tobacco smoke (Z57.31)
tobacco dependence (F17.-)
tobacco use (Z72.0)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Section I.C.9.a Hypertension (page 50), covers I1A
Presume hypertension is linked to heart disease and CKD unless documented as unrelated: use I11, I12, or I13 with additional I50 or N18 codes as directed. Other conditions need provider-documented linkage to be coded as related.

All codes under I1A

I1A can't be used on a claim. Pick a billable code below; grey headings group them.

I1A.0Resistant hypertension

I1A MS-DRGs

As the principal diagnosis, the billable codes under I1A group to MS-DRG 304 or 305 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

Other codes that refer to I1A

Notes on these codes point to I1A.

G31.84 Use Additional Code: hypertension (I10-I1A)
I16 Code Also: any identified hypertensive disease (I10-I15, I1A)
I20-I25 Code Also: the presence of hypertension (I10-I1A)
I60-I69 Use Additional Code: hypertension (I10-I1A)
Z15.3 Code Also: if applicable, hypertension (I10-I1A)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

High Blood Pressure

Blood pressure is the force of your blood pushing against the walls of your arteries. Each time your heart beats, it pumps blood into the arteries. Your blood pressure is highest when your heart beats, pumping the blood. This is called systolic pressure. When your heart is at rest, between beats, your blood pressure falls. This is called diastolic pressure.

Code history

Added in FY2024 (effective October 1, 2023). No changes since.