HARTFORD — A new analysis by Democratic Gov. Dannel P. Malloy's budget office has determined the Republican plan to replace the Affordable Care Act could cost tens of thousands of Connecticut residents their health care coverage if it becomes law.

Released Monday, the analysis also predicts the proposed federal legislation could add as much as $1 billion in annual costs to the state's approximately $20 billion budget after full implementation in 2020. Much of that cost stems from plans to cap federal payments for Medicaid, forcing states to pick up the tab, significantly limit benefits, reduce rates to providers or reduce the number of people served.

For example, Connecticut has relied on additional federal funding to expand its Medicaid program to cover low-income adults. According to the state's Office of Policy and Management, the GOP proposal to eliminate that federal support would require Connecticut to pay five times more for any new beneficiaries, beginning in 2020.

"Health care coverage for some of our most vulnerable populations will be threatened, including seniors, persons with disabilities, children and low-income adults," Malloy said in a statement. "We will see premiums and costs on older people increase and millions of Americans with pre-existing conditions will no longer be able to get affordable coverage."

Nonpartisan analysts project that 14 million people nationwide would lose coverage next year.

In Connecticut, 76 percent of residents — about 85,000 people — who get their insurance through the state's health insurance exchange, Access Health CT, use federal subsidies or cost-sharing to help pay for the coverage. By basing subsidies on someone's age as opposed to income, Malloy's budget office estimates the average person in Connecticut would receive $2,115 less in assistance. Those over age 60 would receive, on average, nearly $5,000 less.

The office projects more than 34,000 Access Health CT customers would not renew coverage in 2018 if the changes take effect.

Republican leaders in Washington have said their aim is to lower costs. They contend coverage statistics are misleading because many people covered under former President Barack Obama's law have high out-of-pocket costs that make health care unaffordable.

GOP President Donald Trump is backing his party's plan.