A draft of the Senate counterpart legislation to overhaul the U.S. health insurance system unveiled Thursday would make drastic changes to the Medicaid program, but largely retain the existing federal tax credit structure from the 2010 health care law that helps individuals afford insurance, among other provisions.

The proposal is part of the Republicans’ seven-year effort to gut former President Barack Obama’s signature domestic achievement. Senate GOP leadership, which has crafted the bill largely behind closed doors with virtually no public input, has faced difficulty in bridging the gap between moderate and conservative demands.

The draft would repeal the law’s individual mandate, which requires people to buy insurance or pay a yearly fine, end several existing taxes created to help pay for provisions in the 2010 health care overhaul, and remove a controversial provision in the counterpart House bill that would allow states to waive out of several of the existing law’s regulations on insurance plans.

While Republican senators have long said they would write their own legislation, many of the provisions included in Thursday’s draft mirror the House language. The nonpartisan Congressional Budget Office has said 23 million people could lose insurance coverage by 2026 under the House proposal.

The draft would also direct up to $50 billion in funding through 2021 to the Centers for Medicare and Medicaid Services that is intended to help shore up the existing individual exchange marketplace. It would also provide another $62 billion over eight years in long-term funding to states.