Older people are being let down by a social care system in which they are "passed like a parcel" between services, a committee of MPs has said.
The Commons health select committee wants local areas in England to deliver "joined-up" care, health and housing.
Funding pressures were reducing older people's quality of life, MPs added.
The government said "urgent reform of the care and support system is needed", and that it was creating the conditions for more integration.
The committee's report said that the Health and Social Care Bill - currently making its way through Parliament - would not simplify a fragmented system in England.
Rather than the current system of multiple funding sources, the MPs are calling for a single local body with the power to commission health, support services and housing.
The precise model would depend on local circumstances, they suggest.
The committee says in its report: "Despite repeated attempts to 'bridge' the gap between the NHS and social care... little by way of integration has been achieved over a 40-year period.
"These separate systems are inefficient and lead to poorer outcomes for older people."
Funding gap denied
Evidence was cited in the report that services which worked together to help keep older people well could potentially save the NHS £2.65 for every £1 spent by, for example, avoiding emergency admissions to hospital.
The committee visited projects which had successfully integrated care in Torbay, Devon, and Blackburn, Lancashire.
However, the report points out that the care trusts that had pioneered integration in these areas are due to lose their commissioning functions under the controversial Health and Social Care Bill.
The MPs acknowledged that the government was putting extra money into social care in England - but said they had still received a "weight of evidence" which pointed to funding pressures and service cuts.
The government's commitment of an extra £2bn a year for social care by 2014/15 was "not sufficient to maintain adequate levels of service quality and efficiency", the report claimed.
In a hearing with the committee, Health Minister Paul Burstow denied there was any gap in social care funding.
The Conservative MP and former Health Secretary, Stephen Dorrell, who chairs the committee, said: "This government, like its predecessors going back to the 1960s, has stressed the importance it attaches to joined-up services.
"Growing demand, coupled with an unprecedented efficiency challenge, makes it more urgent than ever before to convert these fine words into fine deeds.
"It is impossible to deliver high quality or efficient services when the patient is passed like a parcel from one part of the system to another.
"We recommend that the government should place a duty on the new clinical commissioning groups and local councils to create a single commissioning process for older people's services."
Ministers in England are due to publish a White Paper on social care in the coming months.
The committee is calling on the government to implement the findings of the independent Dilnot Commission, which last year recommended a system in which the costs of care for individuals were capped.
MPs warned though that the future of social care should not be "dominated by a debate about the technical details of funding".
They said carers needed more support - but this was too often not identified by staff such as GPs and social workers.
The King's Fund think tank estimates that 890,000 people are not receiving the care services they need - a figure which is disputed by ministers.
A senior fellow at the King's Fund, Richard Humphries, said: "Delivering integrated care must assume the same priority over the next decade as reducing waiting times was given over the last.
"The committee is right to stress that a more ambitious approach is needed to achieve this based on co-ordinated commissioning and pooled budgets.
"We think this could go a stage further by moving towards a single assessment of the funding needs of the NHS and social care in future spending reviews."
The shadow care minister, Liz Kendall, said: "Far from focusing on what older people and their families really need, the government has instead wasted 18 months on its disastrous NHS reorganisation.
"As the committee points out, some of the best examples of integrated care have been achieved by Care Trusts, which will be swept away by the government's own Health and Social Care Bill."
Mr Burstow said: "Integrated care should be the norm. That's why we asked the NHS Future Forum to specifically work on this issue. They told us there is no single silver bullet when it comes to integration.
"What we have already done and continue to do is create the legal and financial conditions for more integration."