Bristol is to fund 18 staff to its Special Educational Needs team to fix what the city council calls a "crisis" in the back-log of assessments.
A report for the authority said it has the worst back-log of children waiting for an Education and Health Care Plan (EHCP) in England.
Statutory assessments of a child should take no more than 20 weeks.
Checks completed in that time have dropped from over 89% in 2016 to below 24% so far in 2019.
The national average is 60%.
The posts were revealed during a meeting of Bristol City Council's cabinet on Tuesday.
Bristol City Council said that "around half of the 18 posts are new" but it has been unable to confirm how many staff work in the department to put that figure into context.
Councillor Anna Keen told the city council's cabinet that the "failures on delivering EHCP's are just not acceptable" and said an independent review will be carried out into the practices and processes.
Bristol mother Jen Smith claims she is being "fobbed off" by the city council despite pleas to help her two disabled children who have missed most of the school year.
Ms Smith's son, 12, has Asperger's and her autistic daughter also has dyslexia.
Both her children are still waiting to get an EHCP completed by the city council.
Her daughter, nine, has been waiting for 46 weeks and her son has been waiting for 40 weeks.
"I've got two disabled children who cannot access school, they're at home, they're self-harming, they're so depressed," she said.
Parent campaign group Bristol Independent SEND Community said it still has "grave concerns" about the SEN management team's ability to reduce the EHCP back-log.
"This plan is fire-fighting at best and at worst, a gross underestimation of the scale of the issue," said a spokesperson.