House Republicans unveiled the replace part of their effort to repeal and replace the Affordable Care Act. Above, federal government forms for applying for health coverage, outside the Jackson-Hinds Comprehensive Health Center in Jackson, Mississippi, Oct. 4, 2013 Jonathan Bachman/Reuters

House Republicans unveiled the replace part of their effort to repeal and replace the Affordable Care Act, lifting penalties against those who don’t buy health insurance, replacing subsidies with tax credits and defunding Planned Parenthood.

The American Healthcare Act keeps two of the most popular features of Obamacare: allowing young adults to remain on their parents’ policies until age 26 and barring insurance companies from denying coverage to people with pre-existing conditions.

House Speaker Paul Ryan, R-Wis., issued a statement saying the legislation amounts to a “rescue” of the healthcare system.

“The American Healthcare Act is a plan to drive down costs, encourage competition, and give every American access to quality, affordable health insurance,” Ryan said.

Senate Minority Leader Chuck Schumer, D-N.Y., however, tweeted the Republican measure merely allows insurance companies to pad their bottom lines.

Republicans have long sought to defund Planned Parenthood because it provides abortion services. Sen. Lisa Murkowski of Alaska already has said she will not support any legislation that strips Planned Parenthood funding, which could make passage problematic since Republicans have only a 52-48 majority in the Senate. Two more defections and the measure would fail if the Democrats remain united in their opposition.

Planned Parenthood President Cecile Richards said the organization will be undeterred in its mission.

Sen. Rand Paul, R-Ky., derided the legislation as “Obamacare Lite.”

Another sticking point is the tax credit provision. Republicans have insisted any subsidies be based on age rather than income. The drafts issued Monday would consider both, the Washington Post reported. It was not immediately clear how the tax credits would compare to Obamacare’s subsidies.

Murkowski and three other GOP senators have said they won’t support any plan that eliminates the ACA’s Medicaid expansion.

"We believe Medicaid needs to be reformed, but reform should not come at the cost of disruption in access to health care for our country’s most vulnerable and sickest individuals," Murkowski and Sens. Rob Portman of Ohio, Shelley Moore Capito of West Virginia and Cory Gardner of Colorado said in a letter to McConnell. They also called for a “gradual transition” to make sure states have time to implement any changes.

"We will not support a plan that does not include stability for Medicaid expansion populations or flexibility for states."

The legislation would keep federal support for Medicaid steady until 2020 when funding for people in the Medicaid expansion group would be reduced to 90 percent. After 2020, the 31 states that expanded their Medicaid programs would continue to get that level of funding for those in the program as of that date. As people drop out, the funds provided would go down.