On June 26, 2017 the Congressional Budget Office (CBO) and the Joint Committee on Taxation (JCT) released their report on the Senate's amendment to H.R. 1628, Better Care Reconciliation Act of 2017, designed to replace the Affordable Care Act (Obamacare). The report indicates the senate version, if passed, would "reduce federal deficits by $321 billion over the coming decade and increase the number of people who are uninsured by 22 million in 2026 relative to current law." By 2026 for people under age 65 under the senate version, 49 million are projected to be without insurance compared with 28 million under the current law. Although the CBO and the JCT state estimates cannot be made with certainty, they conclude "the amount of federal revenues collected and the amount of spending on
Medicaid would almost surely both be lower than under current law" in addition to the number of underinsured people being greater than under the current law.
For more information, read a PDF of their report.