(CNN) -- Eight-year-old Ava Bullard comes bounding out of the Georgia Senate chamber, a smile stretched from ear to ear.
Ava's mother, Anna, bends down to talk to her daughter over the din in the hallway. Her own smile is all business, with a wink to the camera.
"What did he say?" she asks, referring to state Sen. Tim Golden, head of the insurance committee. " Did you tell him we need a hearing?"
"No," says Ava. "But I will!"
This playful moment between mother and daughter would have been unimaginable just six years ago, when Ava was diagnosed with autism. Bullard's spirits were high because news had come that a committee hearing for Ava's Law had been scheduled.
If passed, Ava's Law would require insurance companies to pay for "evidence-driven treatment" -- or treatment that's been scientifically shown to help kids with an autism spectrum disorder. The law would not affect the self-insured plans offered by bigger companies, which cover about 60% of insured people in the state, according to the Georgia Office of Insurance.
At age 2, Ava couldn't speak a word. She didn't respond to her name. She barely seemed to recognize her mother.
"She was staying the same, like she was 6 months old," recalls Bullard.
On the Internet, Bullard found stories about children with autism whose worlds were rebuilt through intense therapy. But when a specialist finally offered a formal diagnosis, Bullard was flabbergasted to hear the doctor tell her she could never afford the price tag for "Cadillac" treatment -- tens of thousands of dollars a year. She soon learned her insurance company wouldn't pay a dime.
Last week was Ava's first visit to the state Capitol, but Anna has been prowling the halls since January. On this day she was flanked by Melissa Solares and Megg Andrade, also mothers with children who fall on the autism spectrum. They swapped stories of conversations with legislators, and handed babies to each other when they got too heavy.
Their effort has set off alarm bells with some insurance companies and businesses, which fear the impact of paying upward of $50,000 per child per year for intensive therapy.
Supporters counter that the short-term cost is modest, and that paying for early treatment could actually save money by reducing the number of children who need long-term assistance. The advocacy group Autism Speaks estimates that autism costs society $126 billion annually. One influential study from 2007 found the average lifetime cost of caring for a person with autism is $3.2 million, most of it due to lost productivity and adult care.
Georgia is one of 18 states that do not require insurers to pay for autism treatment, according to Judith Ursitti, director of state government affairs for Autism Speaks. She points out that several insurers, including TriCare and the Federal Employee Health Plan, with its 8 million participants, have chosen on their own to cover autism therapy.
Autism Speaks, which supports the Georgia legislation, recently did an analysis of 15 states that require autism coverage. In 2010, the second year after South Carolina passed a mandate, nearly 400,000 individuals with autism received assistance; the direct impact on insurance premiums was barely $5 a year. Among all 15 of those states, the annual impact on premiums ranged from $1.20 in Illinois to $9.96 in Minnesota.
But some have a hard time squaring that view with accounts of people like Bullard and Solares spending tens of thousands of dollars a year on treatment.
"We have a situation where health care costs are rising, and health care costs drive premiums," says Susan Pisano, a spokeswoman for America's Health Insurance Plans, the largest industry group.
Pisano says that AHIP does not oppose the specific autism mandate but rather mandates in general.
"We're hearing from employers and consumers that they can't afford to pay any more. At the end of the day, it's not the insurer who pays."
Pisano says the insurance group does not have its own studies on the cost -- or long-term savings -- of paying for autism therapy.
State Rep. Richard Smith, head of the insurance committee in the Georgia House, says state law requires any mandate on insurance companies to go through a special committee to study the impact. Smith hasn't taken a stance on the autism bill, but he says well-intentioned mandates often drive up costs to a point where companies stop offering insurance, hurting the very people the mandates were meant to help.
Ursitti dismisses that concern.
"The states that have had this for a while, like Texas and South Carolina and Indiana -- no one is losing their health insurance," she says. "The sky hasn't fallen. What we do know is that families are accessing care for the first time."
State Sen. John Albers, a Republican who sponsored the Georgia Senate version of Ava's Law, calls it "the right thing to do," but also believes it could save the state a lot of money.
"For those of us like myself who are conservative, this is a huge cost savings because we know what it costs when a child needs to be taken care of throughout their lives," says Albers. With early intervention, "I think we're looking at saving up to a million dollars a year, for each child."
The best-established treatments for children with autism spectrum disorders fall under the broad heading of Applied Behavior Analysis -- often referred to as a "behavioral" approach. While there are many variations, it entails intense coaching to teach basic skills that nonautistic children learn more intuitively, especially skills involving communication.
While details are hotly debated, nearly all experts agree: The key is to start early.
"The earlier you start a child in this treatment, and the more intense the treatment, the better they do," says Dr. Michael Morrier, assistant director of the Emory Autism Center at the Emory University School of Medicine.
In one landmark study, among children who began treatment before turning 3, nearly half improved to the point where they were indistinguishable from same-age peers.
The treatment is intensive, often requiring 30 or 40 hours a week in a one-on-one or small group setting. Providers are in high demand and sometimes have to drive hundreds of miles to see children, further adding to the cost.
Melissa Solares says that she and her husband, a surgeon in Augusta, Georgia, spent $115,000 on treatment the year after their son Arturo was first diagnosed.
A "shadow" accompanies Arturo to school each day, and for up to four hours a day after school another aide helps Solares conduct the formal one-on-one coaching that's the hallmark of behavioral therapy. Twice a week, a more experienced therapist visits from South Carolina to make sure the therapy is being done correctly.
It seems to work: When Arturo was diagnosed at age 4, he still wasn't toilet-trained and could speak less than 50 words, Solares recalls. Barely 15 months later, he's speaking in full sentences and attends a regular, private preschool. "He's a completely different child," Solares says.
Her family is stretched thin. If the Georgia bill doesn't become law, she and her husband will be looking to leave the state for one that requires insurance companies to cover Arturo's treatment.
Despite the financial strain, she feels fortunate. "We have resources, but what do people do who have to work all day, if they can't do therapy themselves?" she asks. "Those children just get thrown in a corner and wasted."
Bullard's parents had a college fund set aside that they let the family use for Ava's treatment. Her church and friends in their Vidalia, Georgia, community also pitched in. "We used all the savings we had, and then some credit cards," Bullard says. "We just did whatever."
There were compromises. For example, Ava got one home visit a month instead of the recommended two or three, and each session with the therapist was shorter.
Even so, it paid off. Within two weeks of her first therapy session, Ava was sitting at the dinner table, something she'd never been able to do. Today, she no longer needs intensive treatment -- just one session a week to practice social skills.
Bullard says a mandate would give other children a chance at the same success Ava's had. "She's in third grade, completely indistinguishable from her peers, because treatment works," says Bullard.
Until getting word of the hearing, the three mothers were feeling glum. Even friendly legislators weren't returning calls. At one point, Solares literally ran down a hallway, baby in arms, chasing a senator who had previously pledged support. He didn't look back.
The promise of a hearing offers a ray of hope. It might be too late to get a vote on Ava's Law this spring, but Albers is looking for another bill where the autism mandate might be attached as an amendment. "Anything's possible," he says.
Back at the Senate chamber, Ava is smiling but tired after getting word of the hearing. Near her breaking point, she turns to her mom and says simply, "I'm ready to go home."