Wall Street is contemplating what's next for the Republican healthcare effort after nonpartisan analysts found it would leave millions more Americans uninsured and a growing number of GOP lawmakers are balking on the legislation.

The Better Care Reconciliation Act would increase the number of people without health coverage by 22 million and cut the deficit by $321 billion through 2026, according to estimates released by the Congressional Budget Office on Monday. At least four Republican senators have signaled they would oppose a procedural vote to move forward with the legislation, throwing the GOP's effort to repeal and replace Obamacare into further disarray.

"The Senate GOP's [healthcare] reform push is clearly slipping, but not all is lost yet as the [$321 billion] in estimated deficit savings over 10 years provides Senator [Mitch] McConnell with broad latitude to grease the legislative skids," wrote Compass Point analyst Isaac Boltansky in a Tuesday note.

The Washington, D.C.-based research firm lowered its odds of the BCRA passing the Senate to 15% from 30% in the wake of the CBO report.

"CBO's scoring of the Senate bill to replace the ACA...provides only a sliver of light through an almost shut door," wrote Jefferies analyst David Windley in a Tuesday note. "That sliver is an additional [$200 billion] of savings vs. the House bill, which gives Leader McConnell some negotiating powder. That said, the opposing forces within the GOP are still running away from one another, suggesting continued challenges in locking down the needed 50 votes heading into the vote expected by the end of this week."

The GOP's House will was estimated to reduce the deficit by $119 billion.

"Politically, the Senate CBO score shows some sensitivity to many of the issues raised by the harder-edged House legislation," wrote Evercore ISI analyst Terry Haines in a note. "The Senate now will grapple in earnest with the basic political and policy questions surrounding those who are thought to lose coverage, the rate of future Medicaid increases, and many other issues that will need to be dealt with before a final Senate vote."

Haines gives Congress 55% to 60% odds of finalizing healthcare reform by the August recess. McConnell has indicated he wants a vote this week, though it's not clear he'll be able to get one.

Insurer Anthem (ANTM) - Get Reportcame out in favor of the Senate GOP's health bill and in a statement said it believes the legislation "will markedly improve the stability of the individual market and moderate premium increases." It said it would work with the government to "navigate the current bill proposes to the Medicaid program," which the CBO estimates the BCRA will cut by $772 billion by 2026.

Anthem, UnitedHealth Group (UNH) - Get Report and WellCare Health Plans (WCG) - Get Report  have only low-single-digit earnings exposure to the Obamacare Medicaid expansion the Senate bill seeks to repeal, Leerink analyst Ana Gupte said in a note on Tuesday. Centene (CNC) - Get Report and Molina Healthcare (MOH) - Get Report would benefit from of the near-term stabilization measures in the legislation but would ultimately see a downside risk because of their higher exposure to Medicaid expansion.

Gupte said the bill offers positive revisions for hospital stocks HCA Healthcare (HCA) - Get Report , Tenet Healthcare (THC) - Get Report and LifePoint Health (LPNT) , and its repeal of the health insurer provider fee presents the most upside for Humana (HUM) - Get Report and Aetna (AET) .

Some analysts pointed to an underlying narrative in the GOP's Obamacare repeal efforts: tax reform. Republicans have set out to tackle healthcare ahead of taxes, and the clock on that is ticking.

"Several GOP Senators are quoted in the media suggesting more time before a vote, but Leader McConnell seems to be in a 'damn the torpedoes' state of mind (a.k.a. let's get on to tax reform)," Windley wrote.

McConnell has warned Trump that if the BCRA fails in the Senate, the GOP will be forced to compromise with Democrats on fixing Obamacare instead, according to a Politico report.

The savings in the healthcare bill, which also includes a major tax cut for the rich, could help Senate Republicans push through more cuts their separate tax legislation. But Boltansky argued that healthcare failure could actually speed up the process on tax reform, which is what investors ultimately desire most.

"The market may view BCRA failing as a near-term negative for the GOP's broader legislative agenda, but we contend that failing to pass health care legislation would dramatically increase the sense of urgency surrounding the tax reform conversation, which would be a welcome sign for investors," he said.