Is I15 a billable ICD-10-CM code?

No. I15 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does I15 sit in the tabular list?

Diseases of the circulatory system (I00-I99), in the block Hypertensive diseases (I10-I1A).

What cannot be coded together with I15?

I15 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

I15

I15 — Secondary hypertension

Non-billable headerICD-10-CM

I15 is a non-billable header ICD-10-CM code for secondary hypertension. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

postprocedural hypertension (I97.3)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

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

Code also

Both codes may be needed to describe the encounter fully. Sequencing depends on the reason for the visit.

underlying condition

Other codes that can never be billed with I15

These codes carry an Excludes1 note pointing at I15. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading I15 alone.

I12Hypertensive chronic kidney disease

Risk adjustment

I15 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead I15

5 child codes. Green means billable.

Questions about I15

Is I15 a billable ICD-10-CM code?: No. I15 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does I15 sit in the tabular list?: Diseases of the circulatory system (I00-I99), in the block Hypertensive diseases (I10-I1A).
What cannot be coded together with I15?: I15 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.