Governor Michelle Lujan Grisham has signed breast density inform bill, HB66 into law, making New Mexico the 36th state to require communication about breast density to women after their mammogram. The law goes into effect July 1, 2019. State bills have also been introduced in Georgia and South Dakota this session.
New Mexico Representative Elizabeth “Liz” Thomson, a breast cancer survivor, was instrumental in introducing and advocating passage of this bill. Governor Grisham’s signature on the bill means that nearly 89% of American women now live in states that require women be provided some level of notification about breast density.
Approximately 40% of women aged 40 and over have dense breast tissue that may hide cancers on mammography. Women with dense breasts may benefit from supplemental screening tests, in addition to mammography, to detect cancers. Women with extremely dense breasts are 4-6 times more likely to develop breast cancer than women with the least dense breasts. Providing women with their breast density classification would enable them to initiate discussions with their physicians about whether supplemental screening might be beneficial.
While the New Mexico law mandates that women be notified of their individual breast density classification, state laws vary in depth and breadth of notification. Not all “inform” laws actually provide women with information about their own breast density; some only provide general information about breast density. There is a growing call for a single national reporting standard to address this disparity. On the federal regulatory level, the Food and Drug Administration anticipates publishing proposed amendments to the Mammography Quality Standards Act (MQSA) regulations for notice or comment. On the federal legislative front, the Breast Density and Mammography Reporting Act of 2017 was introduced in both the Senate (S 2006) and House (HR 4122).
For further explanation about federal efforts and for state-by-state legislative analysis, visit the “Legislative Information” tab at educational website DenseBreast-info.org.
February 18, 2026 
