Avalere has done it again, with a study of how Obamacare plans place drugs for the most serious diseases, as HIV, cancer, and multiple sclerosis — on the highest drug formulary cost-sharing tier. Cop-pays of 40 percent are not uncommon. And the situation is worse in 2015 than 2014. The bar chart below shows how many silver plans (the most common Obamacare plans) place all single-source drugs (that is, branded drugs without generic competition) in a therapeutic category on their most expensive tier. For eight of ten of these categories, a larger share of silver plans do so in 2015 than 2014. For example, 51 percent of silver plans put multiple sclerosis (MS) drugs on their most expensive tier. Last year, only 42 percent did.