Is Z79 a billable ICD-10-CM code?

No. Z79 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does Z79 sit in the tabular list?

Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99).

Z79

Z79 — Long term (current) drug therapy

Non-billable headerICD-10-CM

Z79 is a non-billable header ICD-10-CM code for long term (current) drug therapy. It cannot be billed on its own: choose one of the more specific child codes below.

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.

drug abuse and dependence (F11-F19)
drug use complicating pregnancy, childbirth, and the puerperium (O99.32-)

Code also

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

any therapeutic drug level monitoring (Z51.81)

Includes

Conditions this code covers.

long term (current) drug use for prophylactic purposes

Other codes that can never be billed with Z79

These codes carry an Excludes1 note pointing at Z79. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Z79 alone.

Z92.0Personal history of contraception
Z79.81Long term (current) use of agents affecting estrogen receptors and estrogen levels

Risk adjustment

Z79 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 Z79

8 child codes. Green means billable.

Questions about Z79

Is Z79 a billable ICD-10-CM code?: No. Z79 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does Z79 sit in the tabular list?: Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99).