The MBTA is slated to contribute $94 million to the MBTA Retirement Fund next fiscal year, even as T officials fret that the fund’s fiscal health is “deteriorating rapidly” beyond what they expected.

The annual share the T gives to the privately run pension fund has been steadily growing in recent years and the latest spike is expected to add to the cash-strapped agency’s projected budget gap for the new fiscal year, which begins July 1.

The $94 million contribution marks a $9 million jump from the current fiscal year and is $20 million more than what it gave in 2016, T officials said.

Brian Shortsleeve, the T’s interim general manager, flagged the growing cost as he delivered more bad news on the fund: Its unfunded liability now tops $1.2 billion, a near $350 million spike from just two years ago that’s driven, he said, by under-performing returns.

The pension fund’s board released the new figures to the T following its meeting on Friday. Shortsleeve said it shows that its “fiscal situation is deteriorating rapidly.”

“The fund is actually in worse shape than the baseline that our analysts (used),” Stephanie Pollack, the state’s transportation secretary, said.

Gov. Charlie Baker has filed legislation to shift management of the T’s pension fund to the state retirement system, which he says can cut administrative costs and help restore a fund he once described as being in “free fall.”

Shortsleeve said the fund’s rate of return on investment in 2016 was 6.2 percent, falling below its 7.75 percent goal.

“The unfunded liability will grow in any year where returns are below the target rate,” Shortsleeve said.

Shortsleeve said another 600 MBTA employees will be eligible for retirement as of tomorrow because they have at least 23 years of service. That means the fund’s major problem — it is paying out pensions to more retirees than there are current workers contributing to the system — is likely to grow.

But the T’s largest union, which has members on the pension board, has pushed back on the criticism. Jim O’Brien, president of the Boston Carmen’s Union Local 589 and a pension board member, told the T’s Fiscal and Management Control Board that claims that it is in crisis “simply aren’t true.”

O’Brien, who reportedly has filed to retire this year himself, also laid blame on the T for the imbalance in retirees and current workers. He pointed to a retirement incentive program it offered last year to employees who were eligible to start collecting pensions, pushing hundreds onto the retirement rolls.

T officials say, on average, about 262 employees retire each year from the T. Officials said 372 retired last year.