ICD-10 Code for Routine Screening Mammogram
For a routine screening mammogram in an asymptomatic adult female, use ICD-10 code Z12.31. This is the standard code recommended by the American College of Radiology and other major medical organizations for screening purposes in patients without breast symptoms, signs, or abnormalities 1, 2.
Primary Coding Guideline
Z12.31 is the exclusive code for asymptomatic screening mammography in average-risk women, distinguishing it from diagnostic mammography which requires different coding based on specific clinical indications 1, 2, 3.
This code designates that the encounter is for preventive screening rather than diagnostic evaluation, which has significant implications for billing and insurance coverage 1, 3.
When Z12.31 Is Appropriate
Use Z12.31 for all asymptomatic patients with no breast complaints, palpable masses, nipple discharge, or other breast abnormalities 1.
The code applies regardless of the patient's age (whether 40-49,50-69, or 70+) as long as the mammogram is for routine screening purposes 2.
Z12.31 remains appropriate regardless of breast density, though supplemental screening modalities may be considered in addition 2.
Secondary Codes to Consider
For patients with personal history of breast cancer, add Z85.3 as a secondary code alongside Z12.31 1.
For patients with family history of breast cancer, consider adding Z80.3 as a secondary code to document increased risk 1.
For patients with known genetic mutations (such as BRCA), use Z15.01 as an additional code 1.
For patients with genetic predisposition, Z84.89 may be added 1.
Critical Coding Pitfalls to Avoid
Never use diagnostic breast disorder codes (N60-N65) for screening examinations, even if the patient has a history of benign breast disease 1.
Do not use the general screening code Z12.39 when the more specific Z12.31 is appropriate for breast cancer screening 1.
Avoid using Z01.89 (general examination code) for breast cancer screening as it is too nonspecific 1.
Do not use Z12.31 for diagnostic mammography performed to evaluate symptoms, palpable findings, or follow-up of abnormalities—these require appropriate diagnostic codes based on the specific indication 2, 3.
When to Switch from Screening to Diagnostic Coding
If a screening mammogram reveals an abnormality requiring additional imaging (callback for diagnostic views, ultrasound, etc.), the subsequent visit should be coded with the appropriate diagnostic code rather than Z12.31 1.
For short-interval follow-up of probably benign findings (BI-RADS 3), use the appropriate diagnostic code rather than the screening code 1.
Screening mammograms that result in BI-RADS category 0 (needs additional imaging) transition to diagnostic evaluation, requiring diagnostic coding for the callback visit 3.
Special Populations
For high-risk women under age 40 who qualify for screening, Z12.31 remains the appropriate code, though additional risk factor codes should be included 1.
For transgender patients meeting screening criteria, Z12.31 is still appropriate for breast cancer screening 1.
For patients with prior breast-conserving therapy who have returned to routine screening (rather than diagnostic surveillance), Z12.31 is appropriate 4.