The delay in implementing the cap on care costs is "disappointing" and the Government should draw up a clear timetable for putting it in place to prevent people facing unlimited expenses, a powerful committee of MPs has recommended.
The Commons Public Accounts Committee also warned continued cuts to local authority budgets could result in people not getting the care services they need.
The MPs warned that the squeeze on town hall finances could lead to "cost shunting", with people forced to pay extra for their care requirements or councils cutting other services.
Plans to introduce a £72,000 cap on social care costs from next year have been delayed until 2020 amid fears over how councils would fund the move, which was legislated for in the Care Act.
The Public Accounts Committee said: "It is disappointing that Phase 2 of the Care Act had to be deferred and we are concerned that there are currently no firm plans for its implementation."
The MPs added: "Its deferral until 2020 means that people will have no limit on how much they have to pay for their own care for longer, until the cap on costs is implemented."
The committee welcomed confirmation that the Government would not attempt to claw back £146 million already provided to councils to prepare for the cap but demanded a "clear timetable" for the implementation of the plan.
The way the Department for Communities and Local Government identifies new cost burdens for councils was also criticised in the report.
The committee's Labour chairwoman Meg Hillier said: "The Care Act should mean carers get proper support from local councils, but with budgets squeezed this support will be hard for councils to deliver.
"Local government is taking on more and more responsibilities from central government, but the money does not always follow. The concept of 'new burdens' is simple enough yet the Government's definition of these burdens fails to reflect reality.
"If new costs to councils are not adequately funded then services will suffer. There is also a real danger of cost-shunting - in this instance, costs of providing care falling on other public services, carers or the people being cared for.
"This is an issue of concern to the committee across public services and we will continue to monitor how the Government funds local government."
Between 2010-11 and 2015-16 central government reduced funding to local authorities by around 37% in real terms. Local authorities have tried to protect spending on key areas but have been less able to do so over time.
The Government has calculated that new responsibilities under the Care Act will cost local authorities £470 million in 2015-16 and the National Audit Office has estimated that the Care Act Phase 1 will cost £2.5 billion to implement from 2013-14 and 2019-20.
The Local Government Association warned last week about a £13 billion funding black hole faced by councils following Chancellor George Osborne's spending review, in part due to the escalating cost of social care.
New powers to hike council tax by 2% to pay for social care announced by the Chancellor will ease some of the pressure on town halls, but even if all eligible councils take advantage they will rake in just £1.6 billion more by 2020 - at a cost of £96 a year to the average Band D council tax payer.
A Department of Health spokeswoman said: "We remain fully committed to implementing the cap in April 2020 to help people cope with the potentially high costs of care.
"The spending review gave local authorities access to up to £3.5 billion extra a year by the end of this Parliament, helping to put adult social care on a sustainable footing. Along with this money we will continue to work with the care sector to support it to deliver on this settlement and provide quality care for older and vulnerable people."