The Minister of State with responsibility for Disability has said there will be no additional funding for school leavers with intellectual disabilities this year.
Parents and families of teenagers say they fear day service closures due to cutbacks announced in the latest Health Service Executive Service Plan.
Last year, the HSE provided €10 million to cater for those over 18 years of age needing day services, respite and emergency residential places.
But this year no funding has been allocated for the estimated 650 teenagers due to leave school.
Service providers, who are also taking a 3.7% reduction in core funding, say frontline services are already being affected.
Speaking on RTÉ's This Week, Kathleen Lynch said service providers knew as far back as October and November of last year during negotiations with the HSE and the Department of Health that no additional funding would be available.
She says they agreed to this reduction on the basis that “they would be protected” .
She was critical of what she described as a “crisis-driven service” and said parents' lives were being “thrown into chaos”.
The National Federation of Voluntary Bodies - an umbrella organisation for service providers - says it will be seeking an urgent meeting with the Minister to clarify exactly what was agreed in meetings in the run up to the Budget.
The Federation says that closure of day services and some residential care facilities are among the options it is reviewing.
The HSE says while it makes every effort to provide day services to people over 18, this has always been dependant on the availability of places.