The number of people seeking treatment could double from current levels, depending on how many states expand their Medicaid programs and how many addicts pursue the new opportunity, an Associated Press analysis of government data found.
The surge in patients is expected to push a marginal part of the health system out of church basements and into the mainstream of medical care. Already, the prospect of more paying patients has prompted private equity firms to invest more in addiction treatment companies, a market research firm says. And families fighting the affliction are beginning to consider a new avenue for help.
"There is no illness currently being treated that will be more affected by the Affordable Care Act than addiction," said Tom McLellan, CEO of the nonprofit Treatment Research Institute in Philadelphia and formerly President Obama's deputy drug czar. "That's because we have a system of treatment that was built for a time when they didn't understand that addiction was an illness."
But those seeking a new chance at sobriety may be surprised by the reality behind the promise. The system for treating substance abuse - now largely publicly funded and run by counselors with limited medical training - is small and already full to overflowing in many places. In more than two-thirds of the states, clinics are already at or near capacity.
The new demand could swamp the system before even half of the newly insured show up at the door, causing waiting lists of months or longer.
"Advocates just get so excited, but at some point, reality is going to hit, and they'll find it's not all it was cracked up to be," said Josh Archambault of the Pioneer Institute, a nonpartisan public policy research center in Boston.
Many with substance problems are waiting eagerly for January, when the new insurance will become available.
"It's the chance to clean up and not use anymore, so I could live a stable life," said Ashley Lore, 30, of Portsmouth, Ohio, who was jailed and lost custody of her 4-year-old daughter as a result of her heroin addiction. "If I get into treatment, I get visitation to my daughter back. And I get her back after I complete treatment."
Only about 10 percent of the 23 million Americans with alcohol or drug problems receive treatment, according to the National Survey on Drug Use and Health. Shame and stigma are part of the reason, but about a quarter of them have no insurance.
Philadelphia is better able to give care than most parts of the country, said Roland Lamb, director of the city's Office of Addiction Services.
With some exceptions - most notably methadone maintenance centers, which neighborhoods have fought to exclude - there would be space available in programs ranging from outpatient treatment, the lowest level, to medically managed hospital treatment, the highest.
What has kept beds from being filled is inability to pay for them. Lamb's agency, which serves only people on Medicaid or with no insurance, covers about 27,000 a year, which he said was the bulk of residents in treatment.
"We estimate that there are probably 125,000 that meet the criteria for needing to be in treatment," he said. He guessed that full implementation of the Affordable Care Act, including an expansion of Medicaid, which Gov. Corbett has opposed, might cut that number in half.
But here - as everywhere - insurance can mean the difference between getting care and waiting indefinitely for publicly subsidized help.
Michelle Hines, an Illinois mother, had both experiences when her 19-year-old son became part of a disturbing new trend: suburban teenagers hooked on heroin.
Because he was uninsured, the wait stretched to a month or six weeks for a public bed. His parents, who own a small business, couldn't afford the $2,000-per-month injections to block the heroin high. Outpatient programs cost about $10,000, and a residential treatment stay about $28,000.
Everything changed after her son got coverage under the family's plan because of an early benefit of the Affordable Care Act.
They now pay only $40 a month for the shots that help him stay clean.
"He's working hard at getting his life back together," Hines said. "He's in school full time; he's got a job." (She asked that her son's name be withheld to avoid hurting his job prospects.)
Nine alumni of Hines' son's high school have died from drug overdoses. "A waiting list for a heroin addict could mean death," Hines said. "So many have died waiting, it's awful."
Today, those without insurance include many lower- and middle-income people who don't get the benefit from an employer, don't qualify for Medicaid or Medicare, and can't afford their own policies.
The new law will provide subsidies to help many buy private coverage.
The government is also pressing states to expand their Medicaid programs to include more working poor people. If 20 states expand Medicaid programs - roughly the number now planning to do so - 3.8 million more addicted patients would get insurance, the AP analysis found.
Inquirer staff writer Don Sapatkin contributed to this article.