Birmingham Council's raising eligibility thresholds for adult care to "critical" have been judged unlawful.
In a case highlighting long term care issues brought by four disabled residents, who cannot be named for legal reasons, concerns over the city's cutbacks were upheld by the High Court.
The threshold is the fourth and most severe definition out of mild, moderate, substantial and critical.
The court said Birmingham's proposal to raise criteria from substantial was unlawful because the council had failed to pay due regard to the impact on disabled people, contravening Section 49a of the Disability Discrimination Act.
Birmingham City Council planned to reduce care packages by around 5000 to about 4,000 people over the next three years. The Conservative-Liberal coalition said it needs to cut £118m from its adult and communities directorate and £308m in total.
A spokesman for the council said: "Birmingham City Council will be looking at this judgement in detail and will make a decision on whether to lodge an appeal. The generality of the budget is not affected, this is a decision about the eligibility criteria for adult social care.
Polly Sweeney, solicitor at Irwin Mitchell, the solicitors bringing the case said: "Proposals to cut mandatory duties and tighten eligibility for social care are the major issues in the social care sector."
Claiming a precedent had been set she added: "Other councils up and down the country seeking to target vulnerable groups through cost-cutting drives may be legally challenged."
