That imbalance means the system is just 49.7 percent funded. A fund spokesman said Friday he did not know if it’s ever been that low in a single year, and it’s the first time it’s fallen below 50 percent since at least 1987, according to public records available online.

At the close of last year, the MBTA Retirement Fund’s liabilities climbed past $2.91 billion, more than double the $1.45 billion it reported in assets, according to several documents the fund quietly posted to its website.

The MBTA’s pension system is less than 50 percent funded for the first time in at least three decades, deepening concerns over the long-troubled fund as it mulls handing some financial control to the state.


“That’s the danger zone,” said Mark T. Williams, a Boston University professor who has closely tracked the fund as it has continually spent more than it has brought in. “Then the issue is you can’t continue paying the benefits that you’re paying because you’re going to drain the overall pension, and you’re not going to meet the obligation of future retirees. It’s hard to recover.”

The T pension fund’s gloomy financial picture darkened in 2018, thanks in part to a struggling financial market. The fund reported a negative 3.08 percent return — far below its 7.5 percent target — which helped push its unfunded liability to more than $1.46 billion.

Steve Crawford, a fund spokesman, said officials view the system’s level of funding over five years, not one, where he said it’s slightly better at 53 percent. But even in that context, it’s the lowest since at least the late 1980s, records show.

Crawford argued that the fund is “back on track” this year, when it reported a 9.9 percent net return through the end of April, and is benefiting from “the assistance of greater contributions by members and the authority.”


The Massachusetts Bay Transit Authority is slated to give the fund $118.1 million next budget cycle, according to T officials. That’s up significantly from this fiscal year, when it contributed $103 million in taxpayer- and rider-funded cash.

“We are confident the long-term health of the fund is good,” Crawford said.

T officials forcefully disagree. Brian Shortsleeve, a former MBTA general manager who now sits on the agency’s control board, said the new data should be a wake-up call.

“The MBTA pension [fund] is in crisis. Its financial condition is getting worse, not better,” he said.

After a years-long push by the Baker administration, the control board voted Monday to add the state retirement fund as a potential manager of some or all of the $1.45 billion MBTA pension fund.

That came days after the Boston Carmen’s Union, which represents more than 6,000 MBTA employees, voted to amend its trust agreement to add the state’s Pension Reserves Investment Management board as a fund manager.

That leaves only the MBTA Retirement Fund board itself to vote on adding PRIM as a manager. The six-member panel, which includes three administration appointees and three union-elected members, is scheduled to meet July 19. Crawford said an agenda has not been set, but it could include a vote.

The latest data are far from the first sign of trouble at the fund. Officials reported earlier this year that the fund took a $151 million hit in 2018, and Governor Charlie Baker said as early as 2016 that the system was in a “free fall.” The following year, a T report concluded the system would need $1 billion in additional taxpayer funding over the next 18 years if it is to pay retirees as promised and remain solvent.


Meanwhile, the fund’s liabilities have continued to climb, jumping more than $340 million in the last three years.

For comparison, just five of the 50 state pension funds around the country were funded at less than 50 percent by the end of 2017, according to The Pew Charitable Trusts.

Joe Pesaturo, a T spokesman, declined to say whether the fund’s latest financial picture played into negotiations with the Carmen’s Union. But the agency has long argued that the state system can help make the T fund more “sustainable.”

“The newest valuation reinforces the findings of every recent analysis and report, all of which have warned of the fund’s deteriorating condition,” Pesaturo said. “This is why MBTA management and the control board have been calling for more transparency at the fund since 2015.”

The fund currently has 5,400 active MBTA employees paying into the system and more than 6,800 retirees pulling a pension. James O’Brien, the Carmen’s Union president, reiterated Friday that the lopsided math, and the T’s efforts to cut its workforce, helped push the fund toward its current state.

He also pointed to last year’s markets, where the state’s $69 billion pension system also struggled.


“All pension funds are affected by market forces, thankfully the market bounced back this year,” he said.

Matt Stout can be reached at matt.stout@globe.com. Follow him on Twitter @mattpstout.