Z51.1
Encounter for antineoplastic chemotherapy and immunotherapy
Z51.1 is a non-billable ICD-10-CM code header for encounter for antineoplastic chemotherapy and immunotherapy. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are Z51.11 Encounter for antineoplastic chemotherapy and Z51.12 Encounter for antineoplastic immunotherapy. Its coding notes include a Code also instruction, 1 Excludes1 entry and 2 Excludes2 entries.
Guidelines tips
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
Aftercare Z codes are not used when treatment is directed at a current, acute disease, or for aftercare of an injury. For an injury, the acute injury code with a 7th character for a subsequent encounter is used.
When the encounter is chiefly for the therapy, the Z51 code is first-listed and the malignancy is a secondary diagnosis. For brachytherapy, the malignancy is first-listed and Z51.0 is not assigned.
Code also
Two codes may be needed to describe the condition. This note gives no sequencing order.
- condition requiring care
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- follow-up examination after treatment (Z08-Z09)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
- encounter for chemotherapy and immunotherapy for nonneoplastic condition - code to condition
Also from chapter/block level (1 note)
- follow-up examination for medical surveillance after treatment (Z08-Z09)
Notes
Also from chapter/block level (3 notes)
- Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
- (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
- (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.