Senate Republicans are continuing to work through the details of a bill to repeal Obamacare with just 51 votes, and some are calling for the legislation to include a provision rolling back the law’s Medicaid expansion.

The House sent a reconciliation bill rolling back parts of Obamacare and defunding Planned Parenthood to the Senate last month. Now, lawmakers are debating whether to add a repeal of Obamacare’s Medicaid expansion to the reconciliation bill, while also keeping a full, one-line repeal of the health care law on the table.

Lawmakers are also exploring using reconciliation to roll back Obamacare’s subsidies.

“While Republicans continue to work on a Senate amendment to the House bill, Leader [Mitch] McConnell has said repeatedly he wants to repeal as much of Obamacare as possible,” Mike Brumas, McConnell’s spokesman, told The Daily Signal.

The reconciliation bill passed by the House repealed four of Obamacare’s measures: the individual mandate, employer mandate, medical device tax, and Cadillac tax. It also prohibits Planned Parenthood from receiving federal dollars for one year.

Though Senate Republicans haven’t yet released language for their reconciliation bill—and it’s unclear when they will vote on a bill—there has been disagreement among the GOP ranks regarding the inclusion of a provision to roll back Medicaid expansion.

According to the Huffington Post, 20 Republicans represent 15 states that adopted the Medicaid expansion.

The Daily Signal reached out to all 54 GOP senators and asked if they would support repealing the Medicaid expansion and the subsidies through reconciliation. A handful responded.

Sen. Steve Daines, R-Mont., represents a state where Medicaid expansion was adopted. Though Daines said he respects the decision of the state legislature to expand Medicaid, a spokeswoman for the Montana Republican said he is wary of the program.

“He does, however, have concerns about the long-term sustainability of Obamcare’s expansion of Medicaid and is wary of programs that increase the power Washington may have over states,” Alee Lockman, Daines’ spokeswoman said. “Sen. Daines will continue working in support of repealing and replacing as much of Obamacare as possible, including Medicaid expansion.”

A spokeswoman for Sen. Dan Coats, R-Ind., said the senator was working to determine the best reconciliation bill to roll back Obamacare. Like Montana, Indiana, too, expanded Medicaid.

“Sen. Coats believes we should use reconciliation to repeal Obamacare and is working with his colleagues to find the best possible package to accomplish this goal,” Kristine Michalson, Coats’ spokeswoman, said.

Other Republicans were more explicit in their opposition to attempts to repeal Medicaid expansion.

“I am very concerned about the 160,000 people who had Medicaid expanded in my state,” Sen. Shelley Moore Capito of West Virginia told The Hill. “I have difficulty with that being included.”

“Repealing the Medicaid expansion is not going to be in there because it’s too problematic for many Republicans,” a second Senate Republican, speaking anonymously, told The Hill. “I don’t want to stick the state with the bill.”

Republican leadership can afford to lose support from only three of their GOP colleagues in order to solidify the 51 votes needed to pass the reconciliation bill. Thus far, three senators pledged last month to oppose the legislation unless it fully rolls back the 2010 health care law.

“With millions of Americans now getting health premium increase notices in the mail, we owe our constituents nothing less,” Sens. Ted Cruz of Texas, Mike Lee of Utah, and Marco Rubio of Florida said in a statement at the time.

Neither Cruz’s nor Rubio’s office returned requests for comment on whether they would support a repeal of the Medicaid expansion and the law’s subsidies.

A spokeswoman for Lee said the Utah senator supports rolling back both.

Though Parliamentarian Elizabeth MacDonough ruled that the House reconciliation bill can be fast-tracked, Democrats can still object to provisions of the legislation under the Byrd Rule. Budget experts on both sides of the aisle have warned that parts of the House reconciliation bill, including Planned Parenthood’s defunding, may not pass the test.

Under Obamacare, adults who earn less than 138 percent of the federal poverty line—roughly $16,000—can enroll in Medicaid through its expansion. Thus far, 30 states and the District of Columbia opted to expand Medicaid. One state—Utah—is discussing adoption of the expansion.

The federal government is covering all of the costs of Medicaid expansion until the end of 2016. However, participating states are required to cover 10 percent of the costs by 2022.

Kate Scanlon contributed to this article.