Even more concerning are the children who never make it into the classroom.
"Sometimes if the child has a disability, the family will view it as an embarrassment, so they don't bring the child out," says Phillips.
In such cases, the child may never be identified. Phillips knows it happens, because such children have been found, by chance, on her watch. Schools have conducted home visits to another child in the family only to discover a sibling who was not enrolled in school.
This has been improving as the community has become more educated, she says. But with recent immigration sweeps, Phillips fears that the situation may be getting worse again.
"I would say with the anti-immigrant activities, it's probably getting more common than what it's been in the past," she says. "The pendulum may be swinging back."
Getting diagnosed is just the beginning.
Sandra Catalan first noticed problems with her third child, Leonardo, when he was about 10 months old. A beautiful, chubby baby with soft, downy hair and long black lashes, he didn't like to be held or touched — not even by his parents. He'd cry and throw tantrums when she tried to kiss him.
Catalan remembers those days with a shudder.
"There was nothing I could do to help him. I felt so helpless," she says.
Still, she tried. Catalan lost track of the number of doctor visits before Leonardo was finally diagnosed with autism. She guesses they must have gone at least 10 times.
"Every time we went to the doctor for a routine visit, I'd tell them that there was something wrong with my child," she says. "They never listened."
When Leonardo was finally diagnosed at 4, she was relieved. Finally, her son could get help. From here, she figured things would just get easier.
She was wrong.
Few families — even those in the middle-class income bracket — can afford to pay for therapy out of pocket. The price tag for speech and occupational therapies alone can run well above $50,000 per year. For Catalan, whose day job was cleaning office buildings in downtown Phoenix, it was out of the question.
For lower-income families with children with disabilities, there's AHCCCS, a state program that administers Medicaid, designed to pay for all the services required by a child with special needs.
The maximum salary a family can make in order to qualify is $1,200 per month. The first time she applied, Catalan was denied — her income was too high by $5. So she got her company to dock her hours for two months. The next time she applied, she qualified.
Language barriers can impede the application process, which also requires a child to pass a screening.
Steve Meissner, public information officer for the state Department of Economic Security, which runs the Division of Developmental Disorders, says that all screeners sent to test Spanish-speaking children either speak the language or bring a translator.
But some of the families interviewed for this story had different experiences. Several say that the screeners didn't speak their language — a big problem when part of the screening tests speech delay.
Some of the mothers reported that they were unable to communicate with the tester at all. For one family, it took several screenings before their child would finally qualify.
Nor does the DDD always do a good job of walking families through the process of finding the services they need once the families finally qualify to get them.
Catalan's first visit to DDD was overwhelming. She says they told her how many hours of music, occupational, and speech therapy her son qualified for and gave her a thick packet of papers with the contact numbers for local companies that provided therapy. No one walked her through the steps.
They also told her not to hope for too much: Leo, they said, would never go to the bathroom on his own. He would never play with toys, hold a fork, or dress himself. He would probably never talk. He would never hug her, never want to be touched or kissed.
Catalan refused to believe them — she says she clung to the hope that one day her son would let her hold him. That one day, he might even hug her back.
Armed with the list of therapy providers and not much else, Catalan estimated that she initially called close to 20 programs. Many of the companies didn't even have Spanish-speaking receptionists; sometimes they'd hang up on her. Even fewer had Spanish-speaking therapists. The few that did had waiting lists of as many as 100 children.