Mitch McConnell J. Scott Applewhite/AP Images The latest push by Republican to repeal and replace Obamacare would leave millions more without health insurance and likely cause costs to rise for Americans in the individual insurance market, according to a study published Wednesday.

The Graham-Cassidy-Heller-Johnson (GCHJ) legislation would change the way the federal government spends billions of dollars in federal healthcare funding. The shift would likely produce massive effects on the coverage and cost of Americans' health insurance.

The left-leaning Commonwealth Fund on Wednesday released an analysis of the GCHJ plan by using previous CBO scores for similar bills and other studies.

Here are the major findings from Commonwealth's Sara Collins:

15-18 million more uninsured in 2019: The bill's repeal of the individual mandate, which compels people to sign up for insurance, would have immediate effects when it goes into place in 2019. Based on previous CBO scores of similar provisions, the jump in the number of people without insurance compared to the current system would be as high as 18 million in the first year.

The bill's repeal of the individual mandate, which compels people to sign up for insurance, would have immediate effects when it goes into place in 2019. Based on previous CBO scores of similar provisions, the jump in the number of people without insurance compared to the current system would be as high as 18 million in the first year. 32 million more people uninsured after 2026: The bill also would shift funding for Obamacare's Medicaid expansion and individual insurance market subsidies into a lump sum given to states every year. The bill, however, simply cuts off those grants after 2026. Commonwealth said the roughly 32 million people projected to be beneficiaries of these programs would simply be cut off after that date.

The bill also would shift funding for Obamacare's Medicaid expansion and individual insurance market subsidies into a lump sum given to states every year. The bill, however, simply cuts off those grants after 2026. Commonwealth said the roughly 32 million people projected to be beneficiaries of these programs would simply be cut off after that date. Significantly higher premiums: Commonwealth also said previous CBO breakdowns of a mandate repeal showed premiums increases of 15% to 20% in the first year. " The majority of that increase would come from the repeal of the mandate penalties: insurers would expect that those who remained in the pool would be the least healthy," Collins wrote.

Commonwealth also said previous CBO breakdowns of a mandate repeal showed premiums increases of 15% to 20% in the first year. " Undercut protections for people with preexisting conditions: States could apply for waivers to States could apply for waivers to relax some of Obamacare's regulations if it brings down costs. While the bill does say the state has to continue to provide "adequate and affordable" coverage for people with preexisting conditions, Commonwealth said the leeway for the waivers could lead to the elimination of Obamacare's protections for these people. "It would allow states to apply for waivers that would let insurers charge people with health problems higher premiums, and change other ACA consumer protections such as bans on lifetime benefit limits and comprehensive coverage requirements," Commonwealth said.

A Congressional Budget Office score that includes the full effects of the bill on insurance coverage and individuals' cost burdens will not be ready in time for a vote. Republicans can only pass it without being blocked by a Democratic filibuster until the end of the month.