It would not be surprising that low income people on Medicare would be less likely to get screenings of any type including colonoscopies. But the possibility that this is because of lack of supplemental insurance is incorrect as are almost all the statistics in this UPenn-based article concerning Medicare basic and supplemental insurance coverage.

Most important, most low income people on Medicare are dual eligible for Medicaid and for them, everything -- screenings and treatments -- are covered. People who are just above the level of income that would give them full Medicaid are eligible for free Medicare Part B and most of those people then use that saving to get supplemental insurance. And a disproportionately large percentage of low income people on Medicare not eligible for Medicaid sign up for zero-premium Part C Medicare health plans. These Part C health plans are networked and require typical co-pays. But the co-pays are similar to the co-pays paid by almost everyone not on Medicare who has employer sponsored insurance (ESI) or Obamacare.

At the other end of the scale, when the article says 14% of people on Medicare do not have supplemental insurance, that statistic is not adjusted for the fact that most of that group is still working (or a spouse is still working) and that they are covered by ESI.

The last paragraph makes no sense.

It is quite disturbing when a group from a place like Penn studies Medicare but lacks basici understanding of who Medicare works