Two years ago, the T estimated it was losing $42 million a year from riders who were not paying fares; the bulk of it, about $35 million, lost on the commuter rail system. The transit agency says the annual loss has dropped to between $10 million and $20 million.

Last November, in an effort to capture some of that lost revenue, the MBTA completed a $723 million deal to outsource its entire fare collection system to Cubic Transportation Systems of San Diego. The company will install new fare gates that will open with the tap of a Charlie Card, credit card, or smartphone and will also work on buses and trolleys.

Cash will no longer be accepted aboard T vehicles. Instead, riders will be able to buy Charlie Cards and add value to them. Passengers will also be able to download the corresponding smartphone app and pay their fare.The T has promised that new kiosks will be installed at every train station and a variety of neighborhood stores near bus stops.

Laurel Paget-Seekins, director of fare policy for the MBTA, said customers will have Charlie Card accounts. So, if they lose the card, they don’t lose the value on it. The new system will speed up travel because passengers will be able to pay as they board by just tapping their cards or phones. Having one common card will permit much easier transfers to other parts of the transit system, she said.

The new system is known as AFC 2.0 and will be rolled out over the next two years. This fall the MBTA began a series of meetings across eastern Massachusetts to inform the public about the new fare system and get their reaction to it. At the first of these meetings in Mattapan, Pamela McLaughlin worried that the tech-based ticket system may leave some people behind.

“So that if [passengers] don't have a smartphone, and they tend to be older, they tend to be lower income, they tend to be less educated and those are also the people who don't have much voice," McLaughlin said.

But MBTA program manager Dave Sikorski said people will still be able to use cash.

“The only real difference is you can't pay with cash on the bus, but you can still use cash at the fare vending machines to get your ticket so it shouldn't be any more hardship for those folks,” he said.

A harder sell may be the proposed cost of a Charlie Card. Once free, the new cards may cost a few bucks, which is a model used by other major cities. Paget-Seekins says the reason for the charge is to provide a form of overdraft protection for customers, so they won’t be left stranded if the card’s value drops to zero. But, realizing the upfront charge could be a hardship for some, free or reduced cost cards will be made available.

It may be easier to pay with the new system, but it is not foolproof. As more passengers are allowed easier access through all doors of a train or bus to speed the ride, conductors could have a harder time checking to see if everyone has paid.

Dave Sikorski said for that reason, additional inspectors will be needed, and they will be equipped with hand held devices to make sure customers tap their cards.

Tory Mazzola, a Keolis spokesman, said there is one thing that definitely discourages fare evasion — and that is to impose fines, as done on other transit systems.

As Mazzola said, “if you're caught without a ticket on a train, the impact is real."

Residents in Mattapan wondered how such fines would be enforced. All this talk about penalties and fares is part of the policy discussion taking place now before the new system is put into effect next year.

The MBTA is open to feedback through its website or at any number of public meetings being held throughout eastern Massachusetts this fall.