The Z score indicates that amount of bone you have compared with other people in your age group and of the same size and gender. A negative value indicates that you have thinner bones and weaker bones than the average of the people in your group. The more negative the number is, the less bone density you have compared with others in your group. A positive value means you have higher bone density and stronger bones than the average of the people in your group.
Who should have a DEXA scan?
- Women over 65 years old, regardless of risk factors
- Postmenopausal women with one or more risk factors for osteoporosis
- Women who have been on hormone replacement therapy for prolonged periods
- All postmenopausal women who have had a broken bone
How much radiation exposure is there with a DEXA scan?
The amount of radiation a patient is exposed to is quite small. It is approximately 1/30th that of a chest x-ray, which is comparable to the naturally occurring radiation you are exposed to in one week.
Will my insurance cover the cost of a DEXA scan?
A DEXA scan costs approximately $300. Many insurance companies cover the cost, but check with your insurance provider for the specific coverage you receive. Medicare began coverage of screenings in 1998. A repeat screening is covered once every 24 months. Medicare will also pay for a DEXA in specific situations other than screening, including:
- Patients who have been noted to have “thin bones” or certain fractures on a conventional bone x-ray.
- Patients who are taking more than 7.5 mg of prednisone per day.
- Patients with an overactive parathyroid gland.
- Patients already taking an FDA approved drug for the treatment of osteoporosis to see how well it is working.

