Two Republican senators are working on legislation that would let states decide whether they want to keep Obamacare or move to a different system.

Sens. Bill Cassidy of Louisiana and Susan Collins of Maine both hinted on the Senate floor Tuesday about a bill that would preserve Obamacare, but only for states that choose to keep it. The move comes as the GOP-controlled Congress is pushing to repeal the law, but some Republican senators are concerned about repealing the law without an immediate replacement.

Cassidy said the bill would be essentially the same as a bill he introduced in the last Congress called the Patients Freedom Act. It lets states decide if they want to stay in Obamacare if it is working or leave.

"The state could go with the alternative, which we will lay out, the state could opt for nothing — no Medicaid expansion and no help for lower-income folks — or the state could opt to stay in Obamacare," Cassidy said.

Cassidy laid out a timeline for implementing his system.

Obamacare would be repealed this year, but legislation would allow state legislatures or governors in 2018 to choose the option they "wish to enroll the people of their state," he said.

In 2019, the state would implement the replacement option or their choice and by 2020 the repeal and the replace would be finished.

Collins said she is pleased with a growing consensus in the House and the Senate to provide healthcare reforms at the same time Obamacare is repealed.

"My concern with the repeal and delay plan is that the Obamacare exchanges, already on very shaky financial grounds, would go into a death spiral as consumers would face uncertainty and insurers would have no basis for pricing their policies," she said.

Collins and Cassidy haven't introduced the legislation, but it would be the latest replacement plan from the Senate. Nor did they divulge what the alternative to Obamacare would be.

Sen. Rand Paul, R-Ky., teased details of a replacement plan over the weekend that shared similarities of other GOP plans including expanding health savings accounts. Paul also shared concern about repeal and delay, saying his plan could go into place the same time repeal occurs.

The competing plans comes as committees in the House and Senate are drafting legislation to repeal Obamacare via reconciliation, which enables a bill to be passed via a 51-vote majority instead of the 60 votes required to break a filibuster.

No legislation has been introduced, but some in the GOP have suggested keeping Obamacare in place for a few years until an alternative has been approved.