Calls have been made for enforced national guidelines on non-residential care charges after "huge variations" across local authorities were highlighted.
Jackie Baillie, convener of the cross-party group on Learning Disability, sent a Freedom of Information request to all 32 Scottish local authorities.
It provided them with three scenarios and detailed information on the benefits each client received.
The information supplied by local authorities, giving the level of charges that they would charge in each scenario, showed that despite guidance from local authority umbrella body Cosla intended to standardise charges, there were "huge regional variations" across Scotland.
One example was a single person with nine hours a week support. The amount charged for home care varied between nothing in some local authorities and nearly £95 a month in Clackmannanshire.
Ms Baillie, the Labour shadow health secretary, said: "The Scottish Government must take action to end the postcode lottery for care charges.
"I want to see a much greater degree of consistency in how charging policies are applied across Scotland.
"It is unfair that a couple living in Moray would pay £289 a month while a similar couple in neighbouring Aberdeenshire would pay only £17 a month.
"For even the simplest case study, a single person with nine hours a week support, the amount charged for care varies between nothing and nearly £95 a month. This is a big discrepancy for someone with a limited weekly income.
"Ministers should bring forward clear and consistently enforced national guidelines to ensure that people in every part of Scotland are treated fairly."
However, health minister Shona Robison said: "What Jackie Baillie is conveniently forgetting is that these self-regulating charges were introduced by Labour in 2002, but she never criticised her own government for that position at any stage over the next five years.
"Cosla's guidance recommends a consistent framework for charging and encourages councils to demonstrate that in arriving at charges they have followed best practice.
"The guidance is not prescriptive and it is for individual local authorities to decide their charging policies in keeping with local accountability.
"Cosla agreed to review the guidance on a regular basis. It is currently under review and the Scottish Government is represented on the review group."
