Pennsylvania will become the 27th state to expand Medicaid next year after Republican Gov. Tom Corbett (R) struck a deal with the Obama administration. The agreement was announced Thursday and made Corbett the ninth Republican governor to accept the policy, which has divided the GOP since it was made optional in 2012. The expansion will cover half a million low-income Pennsylvanians. Premiums will be levied for adults above the poverty line starting in 2016, but federal regulators said they must not exceed 2 percent of household income. These specifics were part of the agreement between federal health officials and Corbett, who had previously resisted the expansion on the grounds that states will have to eventually pay for 10 percent of the cost.