The number of adults diagnosed with autism has risen sharply in recent years. In Pennsylvania, the increase has been six-fold since 2005.  By 2015, the state expects to have 10,000 adults with this developmental disorder. Services for adults with autism are already spotty.

Susan Epstein is a pro at advocating for her 20-year-old daughter, Sarah, who has severe autism and intellectual disability. Epstein has done it for years, tracking down the research, hustling up the resources, working the phone lines. She has filed endless paperwork, and eventually found placement for her daughter in a residential facility where she is very happy. But right now, Epstein is hitting a wall, and she feels like a failure.

Here is the situation. Until people with autism reaches the age of 21, their home school districts pay for services, under the Individuals with Disabilities Education Act, which guarantees a free public education. But once they are 21, that funding stream ends, and Epstein says they pretty much fall off a cliff. When Sarah turns 21 later this year, she may have to move out of the place where she has lived since she was 13, and have no place to go.

Nina Wall Cote who directs Pennsylvania's bureau of autism services says that is not unrealistic. "That's absolutely something that could happen, that we wouldn't want to happen, but that could happen given how strained the systems are right now." Cote said.

Many parents, even ones who've long advocated for their children, don't know about the age 21 cutoff, adds Dr. Todd Harris, director of autism services for Devereux Pennsylvania, a non-profit care provider. (In the interest of disclosure, Devereux is an underwriter for WHYY)

Harris says his organization conducted a recent survey and about 60 percent of families were unaware that those entitlements stop at 21. That means a lot of times, individuals don't have services lined up when they turn 21, and it takes them quite some time to get services. In the meantime, says Harris, a lot of individuals just stay at home.

Programs developed specifically for adults with autism do exist, but space is limited, and people end up on long waiting lists. And the competition for scarce slots is only going to heat up, says Nina Wall Cote. She quoted from an autism census her department conducted in 2005: "We will be seeing, in Pennsylvania, and I think this trend will play out nationally as well, almost a 700 percent increase in the number of individuals living with autism who will be reaching the age of 21 within the next five or six years."

In Pennsylvania Governor Corbett's budget proposal, autism funding holds steady, but won't keep pace with the growth of cases.

Autism affects people in a wide range of ways. Some people are non-verbal, and also have intellectual disabilities. Others have a normal or above average IQ, but have debilitating problems with social interactions and anxiety. Brad Mallory is a 22-year-old living with autism. He was happy to be done with high school, but had nowhere to go and nothing to do afterwards.

Dr. Todd Harris says that's not an unusual experience, about 40 percent of adults with autism are not accessing any services. He explained that when adults with autism stay home, they lose skills they learned during high school, and can become very isolated:

"The longer they are in that situation, the more difficult it can be to get them back into the community, because they don't want to go into the community because of anxiety and other issues," said Harris.

Harris says schools are starting to prepare older students for the time after high school is over. Nina Wall Cote urged parents to stay one step ahead of the game, even though she knows that's hard to do. "You spend most of your life as an adult, and you think about what's invested at the front end to get a child, an individual to a place where they are approaching adulthood with some good solid skills, to have all that disappear is a real problem," Cote said.

Susan Epstein continues to search for solutions for her daughter Sarah, but with a rising sense of desperation. "I'm at the crest of a wave, and five years from now, the five is going to be pouring down, and people are going to have to do something about it, but I'm at the very crest so I'm in the front," Epstein said.

Cote says state governments will not be able to provide all of the answers, and cover all the costs for services going forward. She says families, government, businesses, and communities will have to work together to come up with creative solutions to this growing problem.