Which of the following services is covered by Medicare as a preventive screening?

Mammograms are specifically covered by Medicare as a preventive screening service. This aligns with the program's focus on early detection of breast cancer and is part of their preventive services designed to promote health and wellbeing among beneficiaries. Medicare provides coverage for annual screening mammograms for women age 40 and older, which is crucial for identifying potential issues before they develop into more serious health problems.

While cholesterol testing and bone density scans may also be covered under certain conditions, they are not classified universally as preventive screenings in the same way that mammograms are. Elective surgeries, on the other hand, do not fall under preventive services, as they are typically performed based on a medical necessity following diagnosis rather than for screening purposes. This differentiation highlights why mammograms are specifically recognized as a key preventive screening service under Medicare guidelines.