Z17.31 Human epidermal growth factor receptor 2 positive status

Billable ICD-10-CM code, FY2026. Exempt from present-on-admission (POA) reporting.

Applicable to

• HER2+

Applies from Z17 Estrogen, and other hormones and factors receptor status

Code first

• malignant neoplasm, such as:
• malignant neoplasm of breast (C50.-)
• malignant neoplasm of ovary (C56.-)

Notes

• Use one code, as available, for each receptor: Z17.0, Z17.1, Z17.2-, Z17.3-

MS-DRG index

Defines the logic of DRG(s) 951 in MDC 23.

Medicare Code Edits (MCE v43.1 (April 2026))

• Unacceptable principal diagnosis: These codes describe a circumstance which influences care but is not a current illness or injury, or capture only an underlying condition, and are unacceptable as principal diagnosis.

Code annotations containing back-references to Z17.31

Back-references to Z17

• Use Additional: C50 Malignant neoplasm of breast ("code to identify estrogen, and other hormones and factors receptor status (Z17.-)")

Diagnosis Index entries for Z17.31

• Status (post) › human epidermal growth factor 2 receptor › positive

Nearby codes

• Z17.1 Estrogen receptor negative status [ER-]
• Z17.2 Progesterone receptor status
• Z17.21 Progesterone receptor positive status
• Z17.22 Progesterone receptor negative status
• Z17.3 Human epidermal growth factor 2 receptor
• Z17.31 Human epidermal growth factor receptor 2 positive status (this code)
• Z17.32 Human epidermal growth factor receptor 2 negative status
• Z17.4 Combined receptor status
• Z17.41 Hormone receptor positive
• Z17.410 Hormone receptor positive with human epidermal growth factor receptor 2 positive status
• Z17.411 Hormone receptor positive with human epidermal growth factor receptor 2 negative status