The budget office said delaying the mandate by a year would cut federal Medicaid spending by nearly $17 billion over the next 10 years because fewer people would sign up for coverage.
The delay would cut roughly $9 billion from the cost of new tax credits to help low-income households cover the cost of their premiums, the CBO said. Delaying the mandate would also increase federal revenues.
The number of uninsured Americans would climb by 11 million if the mandate were delayed, according to the agency, leaving roughly 55 million people uninsured.
The budget office also said the delay would cause insurance premiums to rise, but because subsidies would still be available to people who did sign up, "the market would not be subject to an unsustainable spiral of rising premiums," CBO said.