An Obamacare overhaul bill would reduce the federal spending by $133 billion over the next decade, according to a score from the Congressional Budget Office and Joint Committee on Taxation released Monday.

The report also found, however, that millions of people could lose comprehensive health insurance that covers high-cost medical events over the same period. “That number could vary widely depending on how states implemented the legislation, although the direction of the effect is clear,” CBO said.

The score does not include information about some of the legislation’s most recent changes, and the scorekeeping agencies said they would need several weeks to estimate what the effect of the legislation on the deficit, health insurance coverage and premiums.

The bill, known as Graham-Cassidy, was introduced by Republican Sens. Lindsey Graham of South Carolina, Bill Cassidy of Louisiana, Dean Heller of Nevada, and Ron Johnson of Wisconsin. It would divert $1.2 trillion in revenue from Obamacare to states to craft their own healthcare systems and would give them funding through block grants. The funds would be distributed from 2020 to 2026 and would need to be re-authorized by Congress.