MCMedicalCodingSoftware
Z51.1

Z51.1: Encounter for antineoplastic chemotherapy and immunotherapy

Non-billable headerICD-10-CM

Z51.1 is a non-billable header ICD-10-CM code for encounter for antineoplastic chemotherapy and immunotherapy. 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.

  • encounter for chemotherapy and immunotherapy for nonneoplastic condition - code to condition

Excludes1 inherited from the categories above Z51.1

A category’s note binds every code beneath it.

Written on Z51: Encounter for other aftercare and medical care

  • follow-up examination after treatment (Z08-Z09)

Risk adjustment

No CMS-HCC V28 category: this code does not change a RAF score.

Code history

Unchanged in every release from FY2024 to FY2027.

Code to one of these instead Z51.1

2 child codes. Green means billable.

Other codes under Z51

ICD-10-CMFY2027· effective October 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release: see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.