Two thirds of parents of disabled children have turned down a promotion or taken a lower paid job to balance care and work, according to a new study.
A survey of 1,000 parents by campaign group Working Families also found that nine out of 10 wanted to work.
Of the 73% who were in a job, fewer than two fifths worked for 30 hours a week or more, while over half had reduced or tried to cut their hours to manage their caring responsibilities.
Most of those not in a job had given up work to care for their disabled children and half had been unemployed for at least six years.
Sarah Jackson, chief executive of Working Families said: "There is often an assumption that parents of disabled children will not be in work, which affects the way they are treated by the services around them.
"The sheer cost of childcare means that even if work is flexible enough to cope with the demands of appointments, it is difficult to make work pay, even when you want it to.
"Our research shows there is a lack of suitable childcare, flexible working options, and financial incentives to work. These factors, together with the higher costs of childcare, all conspire to force parents of disabled children to reduce their hours, accept less well paid work or opt out of the labour market altogether.
"This is not only detrimental to the welfare of these families but it also represents a loss of skills to employers and a cost to the wider economy through loss of tax revenues and additional benefit payments.
"Working Families is calling for action by Government, employers and service providers to acknowledge that parents of disabled children can and do want to work alongside caring for their children."