Marylanders’ phone fees could increase to pay for major upgrades to the state’s 911 system under a proposal before the General Assembly.

The measure would increase the monthly surcharge on residents’ phone bills from $1 to $1.25. In addition, each phone line on a family plan would be charged the fee. Currently, people only pay one fee per bill.

Revenue from a fee hike would help the state transition to Next Generation 911, an internet-based system that would improve location accuracy and eventually let callers send video and other multimedia messages to call centers.

“We are still dealing with technology that’s 50 years old,’’ Sen. Cheryl Kagan said Wednesday at a news conference in Annapolis with supporters of her proposal.

Maryland last raised its 911 phone fee in 2003. The state is the only one in the country that charges one fee per bill rather than one fee per device, said Kevin Kinnally, associate director of the Maryland Association of Counties.

“This would bring us in line with every other state,” Kinnally said.

Kagan, a Montgomery County Democrat, chaired a state commission that studied how to advance Next Generation 911 across Maryland. The state’s Emergency Number Systems Board has called for all the state’s 24 call centers to switch to the new system by the end of 2021.

That will be costly. Officials on Wednesday estimated the initial price tag of the modernization could top $40 million. In addition, recurring costs could total roughly $10 million to $15 million annually, said Walt Kaplan of Mission Critical Partners, a consulting firm hired by the state.

Many states have turned to 911 fee hikes to help pay for the shift to Next Generation, said Brian Fontes, CEO of the National Emergency Number Association.

“All states are grappling … with trying to fund a transition,” he said, adding that much of the equipment in today’s 911 centers is “tethered to last-century technology.”

A major goal of Next Generation 911 technology is to improve first responders’ ability to locate people who call for help. It could also let people send texts and videos to 911 if they are in situations where it would be dangerous to make a phone call.

With a cellphone, “I can press a button and I can hail a car, I can order a pizza,” Kinnally said.

“I don’t have to talk to anyone, I don’t have to tell them where I am,” he said. “Not so with 911. … If you’re not able to tell them where you are, they may not be able to find you. That’s unacceptable to us, and it should be unacceptable to the state of Maryland.”

Last year, the state said it was taking steps to let people text 911 across the state. Officials said Wednesday that the service is not yet available except in Frederick County. A spokesman for the state Department of Public Safety and Correctional Services said up to seven additional counties should be able to offer the service by the end of February.

Kagan plans to introduce several bills to address recommendations of the commission. One would touch on the training and retention of 911 employees. Statewide, 13 percent of 911 specialist positions are vacant, she said.

Another bill would restrict access to certain 911 records under the Public Information Act. Kagan said it’s meant to protect victims’ privacy.

Last year, the Maryland, Delaware, D.C. Press Association, of which The Baltimore Sun is a member, opposed a similar bill by Kagan because it was too broad, executive director Rebecca Snyder said.

Snyder said the association is satisfied with the “narrow scope” of this year’s bill, which would shield medical information, as well as the personal information of victims of domestic violence and sexual assault. But the organization opposes a provision that would restrict the public release of “gory or gruesome” images because state law already gives officials discretion to deny access to such images, Snyder said.