Senate Republicans are weighing a two-step process to replace Obamacare that would postpone a repeal until 2020, as they seek to draft a more modest version than a House plan that nonpartisan analysts said would undermine some insurance markets.

Republicans -- in the early stages of private talks on the Senate plan -- say they may first take action to stabilize premium costs in Obamacare’s insurance-purchasing exchanges in 2018 and 2019. Major insurers have said they will leave the individual market in vast regions of states including North Dakota, Iowa and Missouri.

A Senate plan is likely to continue subsidies that help low-income Americans with co-pays and deductibles, said third-ranking Republican John Thune of South Dakota. White House budget director Mick Mulvaney said Thursday the administration hasn’t committed to paying subsidies due in June -- which would create additional uncertainty for insurers as they set rates for next year.