Parents are calling for more robust laws to support young people with disabilities and lifelong health conditions as they leave school.
Campaigners say that youngsters with additional needs face a "cliff edge" at the end of their teenage years.
One person's poor transition into adulthood can cost the public purse an estimated £1m over their lifetime.
Statistics show that they are more likely to be unemployed or end up living in poverty.
Now a bill is going through Holyrood calling for statutory support to aid the transition.
If approved, every young person living with disabilities or serious health conditions would have a tailored plan, and the opportunity to work with a professional up until their 26th birthday.
A dedicated "transitions minister" would be assigned to oversee a national strategy.
Kate Monahan, whose son Wilf has severe special needs, is among the parents supporting the idea.
She struggled to access suitable care for Wilf when his behaviour became more challenging in his mid-teens.
Wilf, now 18, is in residential care in Aberdeen; however Ms Monahan and her husband Jeremy say they had a long journey to get to that point.
They claim they were excluded from Aberdeenshire Council's discussions about his future.
Ms Monahan told STV News: "We turned to the social work service and said we need a bit more help now - and in the end we sort of crashed out of education services and were rescued by adult services, and Wilf had to move across to adult services two years early.
"The process itself resulted in us losing educational placement in order to get care - that would never have happened to a mainstream child.
"It was extraordinarily frustrating, and quite frighteningly inaccessible."
She added: "What about when I'm not here anymore to be this advocate, to be the person speaking out?"
Aberdeenshire Council says it won't comment on individual cases.
Bill Scott, of Inclusion Scotland, said: "Having a good transition, having that young person achieve the objectives they set when they were at school, can really have a huge impact on their health - both physical and mental."
A consultation on the bill is running until the end of next month.