Z51.1Encounter for antineoplastic chemotherapy and immunotherapy

Z51.1 is the ICD-10-CM diagnosis code for encounter for antineoplastic chemotherapy and immunotherapy. It belongs to category Z51 (encounter for other aftercare and medical care), block Z40-Z53 (Encounters for other specific health care) and chapter 21 (factors influencing health status and contact with health services). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within Z51 (encounter for other aftercare and medical care), Z51.1 is specifically for encounter for antineoplastic chemotherapy and immunotherapy. Related codes cover antineoplastic radiation therapy (Z51.0), palliative care (Z51.5), desensitization to allergens (Z51.6), other specified aftercare (Z51.8) and sepsis aftercare (Z51.A).

To report this condition, pick the subcode that matches the documentation: Z51.11 (chemotherapy) and Z51.12 (immunotherapy).

The conditions in its Excludes2 note aren't part of Z51.1, but may be coded alongside it if the patient has both: encounter for chemotherapy and immunotherapy for nonneoplastic condition - code to condition.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.