[jaymon]

Medicare and medicaid have traditionally underpaid regular commercial insurance with the result that more and more doctors have dropped it over the years.

So it makes sense that payments would concentrate around certain doctors that are still accepting it because more people on medicare will go to them simply because they don't have any other choice, especially in areas that have high concentrations of the elderly, like Florida.

[orky56]

Great point. It should be stipulated (perhaps speculatively) that doctors have left Medicare to go with private insurance to make more. Thus some of the ones who still accept Medicare do so since it is still worth their time and effort (i.e. still making the big bucks).