A study in the Annals of Internal Medicine (Hat tip Kit Seelye) finds that people who are uninsured in their 50s and early 60s end up costing Medicare a lot more money when they hit 65. The extra cost is about $1,000 a year -- meaning that the savings would pay almost half the $197 billion it would cost to cover them in the first place.

And because Medicare pays a tad less than half of all health care spending for the elderly, the reduction in total medical spending (not just from Medicare but also out-of-pocket spending and from other insurers) after age 65 may be even greater.

A lot of the costs can be attributed to uncontrolled or poorly controlled diabetes and cardiovascular disease such as hypertension, heart attacks or stroke.The uninsured may also delay surgeries such as joint replacement until Medicare will pay for them."For adults with these chronic conditions," Dr. Michael McWilliams and his colleagues at Harvard Medical School and Harvard School of Public Health wrote," improvements in blood pressure, blood glucose, and cholesterol control associated with gaining coverage may substantially reduce subsequent annual health care costs."

Medicare spends about $5,800 annually on the previously uninsured -- versus $4,770 for the previously insured. Once they entered Medicare, the uninsured group had higher hospitalization rates. 

The study looked only at medical bills -- not at any lost productivity or other indirect costs of illness in the working age, pre-retirement population.