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Breast cancer screening: Painting an accurate picture

15 Mar 2020

Why you shouldn’t use code Z12.39 for routine mammograms

By: Kerry Scannell, CCS, CPC, coding denials specialist

Most ICD-10 diagnosis codes describe the disorder or disease process of the patient. Some codes, such as the ‘supplemental’ or ‘Z’ codes may even describe the type of treatment or testing the patient will be undergoing. These codes may sometimes be the only ones on the lab/radiology order so it is very important that the coding here is accurate.

Screening for breast cancer is a good example of when a Z code generally stands on its own to tell the story to the coder and the payor of what is happening and why.

For example, Z12.31 (Encounter for screening mammogram for malignant neoplasm of breast) is the correct code to use when you are ordering a routine mammogram for a patient. 

However, coders are coming across many routine mammogram orders that use Z12.39 (Encounter for other screening for malignant neoplasm of breast).

Z12.39 is the correct code to use when employing any other breast cancer screening technique (besides mammogram) and is generally used with breast MRIs.

When Z12.39 is documented on an order for a routine mammogram it is rejected by the payor and both Patient Financial  Services and Coding must review and research the billing, procedure, and patient chart to determine what was actually done and why so that the coding can be corrected. 

Please help us by using Z12.31 for screening mammography so that the clinical picture is clear from the start.

We are here if you have any coding related questions, so feel free to email us at