I am a healthy 53 yo and wonder if a bone mass screening is needed. I am post menopausal.?

Possibly. If you have a family history of osteoporosis, smoke cigarettes, drink excessive amounts of alcohol, have had a fragility fracture, have low levels of vitamin d in the blood or takes medications which cause bone loss such as cortisone, gastric acid suppressants, or antidepressants it would be wise to have a bone density test. Otherwise it would be appropriate to have one at 60 years.