Current malignancy versus personal history of malignancy
When a primary malignancy has been excised but further treatment, such as an additional surgery for the malignancy, radiation therapy or chemotherapy is directed to that site, the primary malignancy code should be used until treatment is completed.
When a primary malignancy has been previously excised or eradicated from its site, there is no further treatment (of the malignancy) directed to that site, and there is no evidence of any existing primary malignancy at that site, a code from category Z85, Personal history of malignant neoplasm, should be used to indicate the former site of the malignancy.
Codes from subcategories Z85.0 – Z85.85 should only be assigned for the former site of a primary malignancy, not the site of a secondary malignancy. Code Z85.89 may be assigned for the former site(s) of either a primary or secondary malignancy. See Section I.C.21. Factors influencing health status and contact with health services, History (of)
ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026 (effective October 1, 2025). Published by CMS and NCHS. Reproduced for reference — always verify against the official CMS release.