The MBTA is sliding deeper into a fiscal hole, according to new watchdog report, which calls on lawmakers to bail out the troubled transit agency.

The report by the Massachusetts Taxpayers Foundation says the T faces an “imminent fiscal cliff” and by July 2023, its operating budget will be hundreds of millions of dollars in the red. The group said that would mean substantial fare increases or service cuts.

That’s despite an infusion of $2 billion in federal stimulus money into the MBTA during the pandemic to offset ridership declines.

Meanwhile, capital to fix the T’s infrastructure will dry up by 2024, leaving the agency with a $13 billion shortfall.

“Factoring in climate change costs, the MBTA is short approximately $20 billion for the period from 2023 through 2031,” said Eileen McAnneny, the foundation’s president. “The federal infrastructure bill, if passed, will not meaningfully change this shortfall.”