Special-education students are being blocked from attending the new small high schools opened during the Bloomberg administration, according to a study released yesterday.

The small high schools are supposed to offer a full array of special-education services after two years, but a study by Parents for Inclusive Education found that after three years some small schools did not offer any.

The study follows a state report released last week that listed New York City among the 17 school districts with the worst dropout and graduation rates for special-education students, although the state education commissioner, Richard Mills, commended the city for its efforts to improve special education.

The lawyer for Parents for Inclusive Education, Kim Sweet, a co-author of the study, said students with disabilities also should benefit from “this great new high school reform that promises more individual attention to students.”

According to the report, 11.5% of the 184 small schools open this year offered special-education classes. It also found that 7.5% of the small-school students are special-education students, compared to 10.7% at other high schools.The report relied on interviews with principals, administrators, and parents and a phone survey of a random sample of small schools.

The Department of Education has a policy of not requiring new small high schools to offer full special-education services the first two years, to give them time to build their capacity.

“Within the new school reform effort, the Department continues to build capacity in the new small schools, and is pursuing ways to build on and broaden the early successes of schools that are getting better results with Special Education students,” a statement from the education department released yesterday said.

A parent who participated in the study, Mary Ann Tsourounakis, said she believes her 15-year-old daughter, Zoe, who has Down syndrome, would do better in a small high school, but she hasn’t found any that will accept her.

“My kid will shut down if there’s a lot of chaos and a lot of noise, and a small school would be better for her in the long run,” Ms. Tsourounakis said. “My daughter is not going to be a Rhodes scholar, we all know that, but being able to be in a small group, being able to talk, being able to be listened to is huge.”

The dropout rate for special-education students is 29% and the graduation rate is 18%, according to the state report released last week.