Last May, Gloria Corsino was enlisted by a Spanish-speaking mother who needed help finding an occupational therapist for her son. Faced with an English-only list of therapists to call after his school couldn’t provide the services for her son’s disability, the mother was stumped.

Language wasn’t the only barrier that Corsino, president of the Citywide Education Council for District 75, found when she started calling.

“There was no provider who could take the child on,” Corsino recalled, noting that she dialed up more than 20 private therapists, all of whom told her they were no longer working with the Department of Education and could not help.

Corsino is among the many advocates ready to air their concerns at a special education hearing on Tuesday, which is being convened by the City Council’s education committee and is expected to touch on issues of equity, class sizes, and how best to improve instruction for students with disabilities.

To some, the hearing will be a chance to raise issues about the inequities that were revealed in data provided to Chalkbeat by the Department of Education showing that students living in some poorer and more far-flung neighborhoods received one category of required services less often than other city students.

“It’s unacceptable,” said former high school teacher Mark Treyger, now a City Council member representing Coney Island, where those services weren’t being delivered 2.5 times more often than the citywide average. “This data validates that the ‘outer’ outer boroughs don’t always get their fair share.”

Treyger is one of 13 elected officials sponsoring a bill that will also be up for discussion at the hearing. The legislation would force the city to annually release information about how often it is not meeting the requirements of students’ personalized learning plans.

The City Council doesn’t have the power to force the city to change its policies, but officials said they crafted the bill to mimic legislation that has required the city to reveal more school-discipline data — information that advocates believe has helped reduce suspension rates as the city worked to lower those figures.

“A big part of it is shedding a light on this so we can get to the bottom of this,” said Daniel Dromm, who chairs the education committee. “They’re doing some things that we’re happy about, but I think more needs to be done.”

Corsino’s testimony will focus on a dearth of therapists who can provide “related services,” the type of special-education support that includes physical therapy, counseling, and help for sight or hearing problems. Chalkbeat found that more than 15,000 different services went unprovided at the end of the last school year — about 6 percent of all mandated services. That figure is down 15 percent since 2010, though the numbers have crept up in some neighborhoods, especially in the Bronx.

“These services are a necessary thing to make our students much more functional,” said Corsino, a parent of two high school-aged sons with autism-spectrum disorders. “When you don’t receive those services, you aren’t going to get the outcomes that you could be getting.”

Also under a microscope will be the city’s broader special education reform effort, which has incentivized schools to serve special-needs students whom they might have referred elsewhere in the past. The changes are broad in scope: Nearly one in five city students is classified as having special needs, and over the last two years, the share of those recommended to receive only part-time support has jumped 10 percentage points.

Last fall, the teachers union received 151 complaints from teachers related to special education, a 60 percent increase over the same period a year before. The complaints, first reported by Chalkbeat, reflect the new demands that have been placed on schools by the overhaul.

Karen Sprowal, a parent advocate whose special-needs son is in sixth grade, said that she plans to lobby the education committee to seek more funding in the city’s capital budget for schools to reduce class sizes and hire more staff to help schools with the new guidelines.

Others see the hearing as an opportunity to get beyond the questions of legal mandates and ask questions about what those students with disabilities are learning.

Kim Sweet, executive director of Advocates for Children of New York, is waiting to hear about how the department can help schools lift academic achievement for students with disabilities. Just 6 percent of those students hit the state’s proficiency standard on its English and math exams in the 2012-13 school year, compared to 35 percent of students without disabilities.

“It’s really time to focus on preparing these schools pedagogically to meet the needs of a wider range of students,” Sweet said.