"At that point, I start really cutting back on my prescriptions. There's some I won't even take," said Brewer.
Dr Jeanne Madden and her colleagues at Harvard Medical School analyzed information about Medicare from 2004 through 2006. There was one positive trend -- they found many beneficiaries no longer cut back on essential needs in order to afford medication, because of Part D.
But Brewer doesn't find Part D so helpful. And researchers found many others like him who had to skip pills or cut doses in half just to get by.
"We found that the sickest beneficiaries actually showed no improvement after Part D began, on the measure of pill-skipping due to high costs," said Dr. Madden.
Experts say substantial copayments and having to cover full costs after the first $2,250 is one reason for the hardship. Brewer paid $700 a month last year after his benefits ran out.
"You talk about $700 a month. Just think if I was taking all my prescriptions the way I was supposed to," said Brewer. "It would chew up most of my Social Security."
Dr. Madden says it's not surprising there would be some problems -- but they need to be addressed.
Brewer says Medicare Part D does help to some extent, but for him it leaves a lot to be desired. And by summer, he'll be in the same difficult situation again.
Researchers say about 10 percent of those on Medicare - including a whopping three million low-income individuals - still have no drug coverage. Experts want Congress to reassess which aspects of Part D are working, and which are clearly not.