Screening Mammogram ICD-10-CM codes

Z12.31 (encounter for screening mammogram for malignant neoplasm of breast) is the only diagnosis needed on a routine screening mammogram, billed with CPT 77067 (or 77063 for screening tomosynthesis). It is first-listed and it applies to asymptomatic women with no current breast complaint. Medicare covers one screening mammogram every 12 months under Z12.31 for women 40 and older, and one baseline between 35 and 39.

A mammogram ordered for a lump, pain, nipple discharge, or an abnormal screening result is a diagnostic mammogram (77065, 77066) and must carry the symptom or finding as the diagnosis: N63.x for a breast mass, R92.2 for an inconclusive mammogram, R92.30 for dense breasts identified on imaging. Submitting Z12.31 on a diagnostic mammogram is a denial; submitting a symptom code on a screening mammogram makes the patient owe cost sharing. The order and the radiology report both need to state which kind of study it is.

Risk and history codes are secondary and explain why a patient is screened early or often: Z80.3 for family history of breast cancer, Z15.01 for a confirmed BRCA or other breast cancer susceptibility gene, and Z86.000 for a personal history of in-situ breast neoplasm. A patient whose breast cancer has been fully treated with no current treatment is Z85.3; the annual surveillance mammogram in that patient is reported as Z12.31 with Z85.3 when it is ordered as a screening study, or as Z08 with Z85.3 when it is ordered as diagnostic follow-up. A patient still on tamoxifen or an aromatase inhibitor is still under treatment and keeps the active C50.x code rather than Z85.3.

Z12.39 covers other breast screening, including screening breast MRI in a high-risk patient and a clinical breast exam performed as a standalone screening. Acquired absence of the breast (Z90.11, Z90.12, Z90.13) and prophylactic mastectomy (Z40.01) are status and encounter codes that explain a one-sided or absent screening.