The MBTA is taking a hard look at privatizing its high-cost bus drivers and mechanics as the cash-starved transit agency considers the most dramatic moves yet to cut a crippling deficit, the Herald has learned.

The T’s Fiscal Management and Control Board announced it is targeting overall “operations and maintenance” that make up 85 percent of all annual costs, according to a 17-page report sent to lawmakers Thursday that was obtained by the Herald yesterday.

The report identified several examples of “an area of opportunity” to “actively examine,” including bus operations, where drivers, at $35.86 per hour, are the highest paid in the country, according to an agency analysis.

It also points to bus and train maintenance, with options ranging from teaming with a private company, to taking on some maintenance work, to pursuing what the report calls “full-lease models,” where the T operates, but does not maintain, a fleet of vehicles.

The T employs more than 1,700 full- and part-time bus drivers and 390 machinists, or mechanics.

Two board members said it is too early in the process to say how exactly the T could privatize bus and mechanic service, whether it could mean laying off union bus drivers or mechanics, and putting up for bid major transit routes.

“In my opinion, this is one of the biggest things they can do, putting out to bid the very elements of the T that would allow big savings,” said Greg Sullivan of the Pioneer Institute, who has closely studied costs of the T’s bus operations.

“I’m sure it will get enormous opposition by labor unions at the T, now that they may be going at bus maintenance and operations of some of the lines,” Sullivan said. “But what they’re doing is tough, necessary and very smart.”

Facing a $110 million deficit, the T has thus far sought out private vendors for smaller departments, such as its parts warehouse and its so-called “money room,” in an attempt to save cash.

But under the law Gov. Charlie Baker signed last year, the T has just a three-year window — or through mid-2018 — to identify areas to privatize without the restraints of the anti-privatization Pacheco Law, with signs now pointing to more large-scale moves.

“There is not a magic number here,” said Steve Poftak, a board member. “This is not a willy-nilly rush to outsource stuff. To us, it’s a very thoughtful, kind of step-by-step consideration of how the T does business.”

The move, however, will surely draw resistance, including from within the board itself. Brian Lang, president of Local 26’s hotel and food service union and a board member, said he’s “unconvinced that’s the road to go down.”

“My opinion is that the core functions would be better served if we can control them through the agency, the MBTA,” he said. “I anticipate the next six months we’re going to have a lot of vigorous discussion on this and other issues.”

James O’Brien, the president of the Carmen’s Union Local 589 — the T’s largest union — said leaning on privatization to control costs is “flawed logic.” The union has repeatedly pointed to other problematic private contracts, such as the T’s commuter rail agreement with Keolis, which the board last month approved to pay $66 million more over the life of its contract.

Rafael Mares, a transit advocate and vice president at the Conservation Law Foundation, also raised a red flag, saying, “I feel they’ve been given a tool by the Legislature, by the relief from the Pacheco Law. But now everything to them seems to look like a nail because they’ve been handed a hammer.”