The administration of Mayor Bill de Blasio has rejected federal government findings that the vast majority of New York City’s public elementary schools are not “fully accessible” to children with disabilities, in violation of the Americans With Disabilities Act.

Last month, the office of Preet Bharara, the United States attorney in Manhattan, said that a two-year investigation had shown that six school districts, serving more than 50,000 elementary students, lacked a single school that was fully accessible. Mr. Bharara’s office gave the city Department of Education a month to respond with proposals to “remedy this unacceptable state of affairs.”

In a letter released late on Friday, senior officials of the city’s Law and Education Departments rejected the federal government’s criticism, contending that Mr. Bharara’s office, in its Dec. 21 letter detailing the findings, “inaccurately characterizes the number and geographic distribution of accessible schools, and erroneously concludes that the D.O.E. is not providing program access to students with disabilities.”

“We believe the D.O.E.’s elementary schools, when viewed in their entirety, provide full program accessibility for all elementary students,” the city said in an eight-page response, which was dated Jan. 20 and addressed to Mr. Bharara and two lawyers in his civil rights unit.