Senate Republicans' healthcare bill would result in a federal funding drop on Medicaid from 27 percent to 39 percent by 2036, depending on the state, according to an analysis presented at the National Governors Association.

The analysis, assembled by consulting firm Avalere Health, was first obtained and reported on by Politico.

It finds that federal funding would decline by 35 percent in 15 states by 2036, including in California, Kentucky, Nevada, New Mexico, North Dakota, Oregon, and Washington. In Arizona, Arkansas, Colorado, Ohio, Pennsylvania, Tennessee, and Utah, federal funding for Medicaid would fall by 30 and 35 percent, the report shows.

Before Obamacare passed, states had different requirements for who could qualify for Medicaid, and Obamacare aimed to make states more uniform by saying anyone who is low-income could have access to the program. The Supreme Court, however, ruled in 2012 that the law should be optional for states, and as a result, the District of Columbia and 31 states have expanded the program.

The Senate's healthcare bill, the Better Care Reconciliation Act, would roll back Obamacare's expansion of Medicaid. Over the long term it allows states to choose between receiving a fixed amount of federal dollars from Medicaid as a per-capita cap or a block grant and reconfigures the program's growth rate to match overall inflation rather than to its current, faster-increasing medical inflation. The Congressional Budget Office estimates that these changes would result in cuts of $772 billion in federal spending on Medicaid, and would shed 15 million people from the program.

Some Republican governors have urged senators to oppose the legislation, largely because of the effect it would have on Medicaid.

The Avalere report projected that between 2020 and 2036 switching to a Medicaid per capita cap would cause funding to decline by $535 billion in California and $268 billion in New York. Other large states, like Pennsylvania and Texas, would have cuts of about $100 billion each.