Gov. Charlie Baker has held the fiscal line for Massachusetts taxpayers and those subject to myriad governmental fees, promising no hikes in the fiscal 2017 budget.

“The budget that we’re working on … is not going to include any new fees or taxes in it,” Baker said in early January, a message he reiterated in his State of the Commonwealth address.

Yet for customers of the government-operated MBTA, July 1 could bring a fare increase that averages out to about 9.7 percent. The first public hearing on the T’s fare proposals will be held Monday in Lynn.

While the Baker administration maintains T fares are distinct from fees, opinions held by other officials and experts are mixed on that front, with hints of a partisan divide. The MBTA fares would not be part of the state budget. Baker plans to submit his draft of the annual spending plan on Wednesday.

Subsidized to the tune of nearly $1.2 billion by taxpayers around the state, the MBTA’s finances are tied into the state budget but the agency has its own budget. Lawmakers and transit activists who have challenged the size of the proposed fare hikes have acknowledged some increase would be prudent.

Though they did not opine on the fare proposals, a Harvard professor who Baker appointed to an MBTA task force last year and the president of the Massachusetts Taxpayers Foundation both told the News Service the fares appear to be a form of fee.

“I would think that a fare would be a fee,” said Jose Gomez-Ibanez, a professor of urban planning and public policy, when contacted by the News Service about any distinction. He said, “A fee is a payment for a service.”

The question of whether a T fare is synonymous with a fee appears to have some partisan colorings. Elected Democrats quizzed about the distinction generally said they failed to see one, while Republicans said the MBTA is a special case.

“I think at the end of the day the governor is very reasonable in terms of his approach and what’s going on over there. You’re talking about a totally different kettle of fish over at the MBTA,” said Rep. Todd Smola, the ranking Republican on House Ways and Means. The Warren lawmaker said, “The MBTA is kind of its own animal.”

When it raised gas and tobacco taxes in 2013, the Democrat-dominated Legislature established a framework for regular, moderate fare increases at the T – though there has been disagreement over the specifics of that provision.

“I understand the governor to be saying that we’re not going to finance the operations of state government generally with increases in fees or taxes, but when it comes to the MBTA, we have always expected them to generate a lot of their own-source revenue, and I think raising the fares are consistent with that understanding of how they’re financed,” said Senate Minority Leader Bruce Tarr, a Gloucester Republican. He said, “I think the MBTA is much more of a – or should be much more of a pay-as-you-go operation and I think it’s dis-analogous to other taxes and fees.”

The House and Senate chairmen of the Transportation Committee said a distinction between a fee and a fare is either nonexistent or at least unapparent to the riders being asked to pay more.

“To the person paying it, the word difference is no difference. They’re being asked to pay more for a government service,” said House Transportation Chairman William Straus, a Mattapoisett Democrat. He said the most important metric is whether service is improving – a major area of focus for the Baker administration.

Showcasing the MBTA’s efforts to upgrade track infrastructure ahead of this winter, Baker in September rejected the notion that taxpayers around the state be asked to pay more for Metro Boston’s public transit, citing lack of confidence in the system’s operations.

“I’m not talking taxes, period. Not talking taxes. Because as far as I’m concerned we have a long way to go here to demonstrate to the public, to each other and to everybody else that this is a grade-A super-functioning machine that’s doing all the things it should be doing to maximize its performance and maximize its own-source revenue as well,” Baker told reporters in a Dorchester work yard.