Breast density has emerged as a critical phenotypic marker of increased breast cancer risk. The breast density legislation, passed in multiple states, requires patient notification of the implications of the breast density on breast cancer risk and screening. Supplemental screening may be suggested in the state regulation; however, there are limited data to guide conversations with patients. This article will review the current state of supplemental screening in women with dense breasts and discuss theories of the mechanism of action. Guidance is provided to assist in shared decision making and appropriate patient counseling.