The latest Obamacare repeal bill would result in 21 million fewer Americans having health insurance in 2026, compared to Obamacare, according to a new analysis that seeks to approximate the Congressional Budget Office’s methods.

These estimates from the USC-Brookings Schaeffer Initiative for Health Policy project:

15 million fewer people with insurance in 2018 and 2019, versus current law;

21 million fewer insured by 2026;

32 million fewer Americans with coverage after 2026 if the funding provided in the Obamacare repeal bill from Sens. Lindsey Graham (R-SC) and Bill Cassidy (R-LA) is not reauthorized by Congress.

The analysis may be the best estimates the public and Republican senators will see before they vote on the Graham-Cassidy plan, which would turn much of Obamacare’s funding into a block grant and send the money to states to establish their own health care programs. The plan, Senate Republicans’ last hope to repeal Obamacare before a key September 30 deadline, is expected to lead to billions of dollars in federal spending cuts for health care.

The legislation is being rushed to the floor before the end of the month, after living in relative obscurity since the Senate failed to repeal Obamacare in late July.

Because of the tight timeline, the Congressional Budget Office has warned that it might not be able to provide a full analysis of how many Americans would be covered under the bill or what would happen to premiums.

So the researchers at USC-Brookings sought to replicate the CBO’s methods as best they could to offer an estimate on how the numbers of uninsured Americans would change under Graham-Cassidy compared to Obamacare. The result is much the same as the other Obamacare repeal plans that failed: Tens of millions fewer people with health insurance.

“These estimates are, of course, subject to considerable uncertainty, most importantly because predicting how states would respond to the dramatic changes in the policy environment under the Graham-Cassidy proposal is very challenging,” the researchers wrote in their report. “What is clear, however, is that the legislation would result in very large reductions in insurance coverage.”

Republican lawmakers and their conservative allies have become increasingly dismissive of the CBO’s projections, arguing that the office’s methodology, among other things, overestimates the impact of Obamacare’s individual mandate on coverage. They have gone so far as to say that they would completely ignore numbers from the nonpartisan office tasked with evaluating legislation.