A partial repeal of Obamacare could leave 18 million people who have insurance today with no coverage one year later, according to an analysis by the nonpartisan Congressional Budget Office.
The report estimates that 32 million people would lose their insurance over 10 years.
The CBO based its estimates on a bill passed by Republicans and vetoed by President Obama in 2015. That bill amounted to a partial repeal of the Affordable Care Act, also called Obamacare, eliminating the penalty for people who didn't have health insurance. It also cut out the government subsidies that currently help people pay their premiums.
The CBO estimated that getting rid of the penalty for people who do not purchase insurance would lead to 18 million fewer insured people within a year and that the number would eventually grow to 32 million after subsidies and a Medicaid expansion were also eliminated.
As NPR's Alison Kodjak reported, "congressional Republicans haven't introduced legislation to repeal Obamacare yet [this year], but they've suggested they'll follow the model of the previous  bill."
So far, lawmakers pushing for the repeal have no plan for encouraging people to have insurance without the mandate and subsidies.
"We're not holding hard deadlines, only because we want to get it right," House Speaker Paul Ryan, R-Wis., said last week.
On Monday, President-elect Donald Trump told The Washington Post he was working on a plan to replace the Affordable Care Act with a proposal that would provide "insurance for everybody."
As we reported, "he did not get into any specific details about his health care plan during a telephone interview with the newspaper. But he did say it would be 'much less expensive' and would involve 'much lower deductibles.' "
He also told the newspaper he does not plan to cut benefits for Medicare and that he does not want a single-payer health care system.
The CBO analysis makes clear that repealing Obamacare would affect millions of Americans, even those who do not lose their health insurance outright. The report found that in the first year after a repeal-without-replacement law, premiums would rise about 20 to 25 percent over the levels predicted with Obamacare, which itself has been criticized for its failure to control premium costs.
The analysis also found that without the federal mandate requiring people to buy insurance, some insurance companies would stop offering plans, and in the first year "roughly 10 percent of the population would be living in an area that had no insurer participating" in the market for individuals buying health insurance.
By 2026, that would grow to 75 percent of the general U.S. population.
Although Republicans have already taken steps toward a partial repeal, the marketplaces established by Obamacare are still operating. Open enrollment for 2017 ends Jan. 31, with a few exceptions, as we have reported.