Z17.1
Estrogen receptor negative status [ER-]
Z17.1 (also written Z171) is a billable ICD-10-CM diagnosis code for estrogen receptor negative status [ER-]. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 10 codes in category Z17 (Estrogen, and other hormones and factors receptor status). The Alphabetic Index lists it under 1 entry. Its coding notes include a Code first instruction.
Code first
If the underlying condition listed here is present and known, sequence it first.
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Hospice: not accepted as primary
Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Supplementary or additional code, not allowed as principal diagnosis.
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.
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 1 entry