When Rashaan Payne was 2 years old, his pediatrician noticed that he was not talking at the level of most children his age. After autism was diagnosed, Rashaan began receiving speech therapy once a week at his home on the South Side of Chicago, paid for by the federal and state governments.
When he turned 3 in October, federal law mandated that he leave that program and be evaluated for services within the Chicago Public Schools. But while his mother, Treva Thompson, said she has filed paperwork and repeatedly called the neighborhood school, Rashaan has yet to be evaluated. She is worried that after making progress, her son will lose ground.
"It's like he's at a pause now," said Ms. Thompson, who left her factory job packing ice cream cones to stay home and take care of Rashaan. "When you're dealing with special-needs children, you need to be consistent with whatever you're doing. You can't do something and then stop in the middle of it."
In a complaint filed on Monday with the Illinois State Board of Education, a nonprofit advocacy group says that thousands of children are in Rashaan's position because the Chicago Public Schools have repeatedly failed to evaluate children with disabilities and move them into special education preschool programs.
Under the federal Individuals with Disabilities Education Act, states must provide special education services to 3- and 4-year-olds with disabilities that impede their learning even before they are officially enrolled in school. Usually, local school districts place children in prekindergarten classes or send therapists to visit children at home. Under the law, a plan for services must be in place by a child's third birthday.
Amy Zimmerman, managing attorney for Health & Disability Advocates, which filed the complaint, said parents who apply to have their children assessed at local schools are often ignored or told to wait past that deadline.
"Basically it was any excuse in the book to turn kids away," Ms. Zimmerman said. "It was probably a lack of understanding that these kids actually belong to them. We talked to a lot of special education folks, and they didn't even realize they aren't allowed to say, 'Come back in three months.' "
Across the country, advocates for people with disabilities said that preschool children receive a patchwork of services. In New York, private contractors provide therapy, but state auditors found that companies have diverted government funds to pay for rent and landscaping for executives, among other improper uses.
In some places, the transition from early intervention to preschool special education is smooth, but in others, said James Wendorf, executive director at the National Center for Learning Disabilities, bureaucratic problems lead to delays.
"The handoff to schools is difficult even under the best circumstances," Mr. Wendorf said. "Are they doing the best they can? If they are doing the best they can, their best is not good enough."
In Chicago, pediatricians and coordinators of Head Start programs who work with children with learning disabilities said they also were frustrated at delays in getting children placed in preschool special education programs.
"If you miss those two years, there are huge gaps in what the child could have learned and become school ready," said Dr. Bree Andrews, director of the Center for Healthy Families at the University of Chicago.
In a statement, Robyn Ziegler, a spokeswoman for the Chicago Public Schools, said the district has had "an issue in delivering these services in an adequate manner and, once identified, it has once again become a top priority for C.P.S. to ensure the timely delivery of these services."
She said the district was reviewing its special education operations and has designated $4.5 million for these services. The district has already set up three teams devoted to evaluating preschool-age children, and plans to set up more, she said.
Beth Swanson, Mayor Rahm Emanuel's deputy for education, said the mayor "is committed to ensuring that every child in Chicago has access to early education programs." She added that the city had overhauled how it funds early childhood programs and would focus on improving wait times for special education evaluations as well as train staff at city-funded programs to screen preschool children.
Keisha Allen, whose son, Isaac Lampley, turned 3 in July, hopes he will soon be placed in a preschool special education class. Since a speech therapist stopped coming to his home six months ago, she has applied to his local school and has tried her best to keep Isaac occupied.
She lets him watch children's programs on Nickelodeon and works on helping him identify colors and letters of the alphabet.
"I would rather him be in a classroom environment," Ms. Allen said. "I think he would learn better if he were around other kids who have the same disabilities that he has."
Correction: January 8, 2013, Tuesday
This article has been revised to reflect the following correction: An earlier version of this article misstated Amy Zimmerman's title at Health & Disability Advocates. She is the managing attorney there, not the director.education
This article originally appeared in The New York Times.