Twenty states are set to run their own health insurance exchanges, an additional 13 states are expected to partner with the federal government to jointly operate an exchange and at least one-third are likely to have a federally operated marketplace, Avalere Health says in a report. Governors have the authority to decide which type of exchange to implement, although Missouri voters on Tuesday approved a measure that bars the governor from instituting an exchange without the approval of the Legislature or a voter referendum. The Hill/Healthwatch blog (11/7)