A bill the Senate could vote on next week to repeal parts of Obamacare without a replacement would make the insurance market unstable, increase premiums and increase by 32 million the number of uninsured people, according to an analysis released Tuesday by the nonpartisan Congressional Budget Office.

While repealing billions of dollars in taxes Obamacare imposed to pay for expanding health coverage to more Americans, the legislation would still decrease deficits by $473 billion over 10 years because of the spending reductions.

The bill is similar to one approved by the House and Senate in 2015 but vetoed by then-president Barack Obama.

The legislation would immediately end the Affordable Care Act mandates for people to obtain insurance and also scrap in 2020 the federal subsidies to help pay for them. But it would keep the regulations on what insurers have to cover and the requirement that they not turn down sick people seeking coverage or base premiums on their health status.

As a result, the pool of people buying insurance will be older and sicker, prompting insurers to increase premiums. Insurance plans could cost about 50% more right after subsidies are eliminated and could double in 10 years, the CBO estimated.

Faced with fewer customers with higher expenses, some insurers would likely stop selling plans. About half the country could have no option in the first year after subsidies are eliminated. After 10 years, three out of four Americans might not be able to buy a plan on the individual market, according to the CBO.

The bill would also end in two years the extra federal funding the ACA made available to states to expand eligibility for Medicaid to those earning slightly more than the poverty level. But unlike the bill the House passed and the Senate was unable to bring up, a repeal bill would not reduce federal support for traditional Medicaid.

Still, the repeal of Medicaid expansion is expected to significantly increase the number of people without health insurance.

Because of both the Medicaid cuts and elimination of private insurance subsidies for people who don’t get coverage through an employer, the number of people who are uninsured would rise by 32 million in 10 years.

By 2026, about 21 percent of Americans under age 65 could be without insurance, compared to a projected 10 percent if the ACA is not changed.

The bill would block Planned Parenthood from receiving Medicaid funding for a year. The federal government already prevents Medicaid patients from receiving abortion services. But the bill would also block them from using Planned Parenthood for contraception, testing for and treatment of sexually transmitted diseases, and other services.

The taxes and fees the bill would repeal or delay include those the ACA imposed on investment income, higher earnings, tanning beds, sectors of the health care industry and on high-cost employer-provided insurance plans.