The CBO released its report on Monday, and the numbers weren’t pretty. It estimated that the bill would leave 22 million more Americans uninsured in 2026 than under President Barack Obama’s health care law, delivering a blow to GOP leaders’ hopes of pushing the plan through the chamber this week.

The Republican US senator from Maine had been on the fence about the GOP bill in recent days, saying she wanted to wait for a Congressional Budget Office evaluation before making her decision.

When it comes to the Senate health care bill, count Susan Collins out.

‘‘I have very serious concerns about the bill,’’ Collins had said on ABC over the weekend, adding that the CBO score ‘‘will be so important.’’


On Monday evening, Collins aired her decision on her official Twitter page, saying the Senate bill “doesn’t fix ACA problems for rural Maine” and that she will “vote no.”

I want to work w/ my GOP & Dem colleagues to fix the flaws in ACA. CBO analysis shows Senate bill won't do it. I will vote no on mtp. 1/3 — Sen. Susan Collins (@SenatorCollins) June 26, 2017

CBO says 22 million people lose insurance; Medicaid cuts hurt most vulnerable Americans; access to healthcare in rural areas threatened. 2/3 — Sen. Susan Collins (@SenatorCollins) June 26, 2017

Senate bill doesn't fix ACA problems for rural Maine. Our hospitals are already struggling. 1 in 5 Mainers are on Medicaid. 3/3 — Sen. Susan Collins (@SenatorCollins) June 26, 2017

With Democrats solidly opposed to the legislation, Senate Republicans must find the votes from within to pass the bill. They can afford to lose only two votes, but at least six Republicans — including Collins — have now announced that they cannot support the plan as drafted, and others have expressed concerns.

Before Collins released her decision, five other GOP senators had announced they opposed the bill: Dean Heller of Nevada, who says it cuts coverage too deeply, and four conservatives — Rand Paul of Kentucky, Ted Cruz of Texas, Mike Lee of Utah and Johnson — who say it does not do enough to lower health costs.

Other Republicans, like Collins and Senator Lisa Murkowski of Alaska, had previously expressed misgivings, and Senator Ben Sasse of Nebraska declined to say Sunday how he would vote.

Wire material from The New York Times was used in this report.