The NHS in East Anglia has announced overweight people will be denied knee and hip replacements.
Many PCTs offer guidance on which patients to treat
A look at why this decision has been taken and if it has any relevance for the rest of the health service.
Q: What has happened?
NHS managers in East Anglia have decided obese people - classed as those with a body mass index above 30, which applies to nearly a quarter of the population - will not be allowed to have hip and knee replacements.
The decision by Ipswich, Suffolk Coastal and Central Suffolk primary care trusts, was taken in consultation with local doctors.
It is generally considered more dangerous to anaesthetise overweight patients, who are often asked to slim before going under the knife.
Other thresholds have been set for nine other procedures, including treatment for varicose veins and grommets for glue ear in children.
Q: Is this unusual?
PCTs, which are responsible for three-quarters of the NHS budget, routinely issue guidance on treatment for doctors.
Doctors can decide not to treat a patient if the procedure puts them at greater risk or would not be of benefit.
But what marks out the East Anglia decision is that it has been linked to financial considerations and not just what is best clinically.
Dr Brian Keeble, a director at one of the trusts, said: "We cannot pretend that this work wasn't stimulated by pressing financial problems."
The decision will mean that fewer operations will have to be carried out at the hospital.
The three trusts are facing a £22m deficit this financial year. Their overall budget is £380m.
Q: Is it being opposed?
While the PCTs board has given the green light to the move, patients groups have expressed outrage.
The Patients Association said patients should not be denied treatment for anything other than on medical grounds.
Doctors do not object to guidance being issued, but the British Medical Association said each case should be assessed on an individual basis.
The Department of Health has said it is a matter for local decision-making, although ministers have always maintained attempts to balance the budget should not impact on patients.
Q: Are the financial worries unique to East Anglia?
No. One in four NHS bodies failed to balance the books last year, leaving the NHS with an overall deficit of £250m.
The predicted overspend is expected to be worse this year.
The situation has prompted many trusts to shut wards and cut jobs in a bid to save money, but this is the first time the prospect of rationing care has arisen.
Q: Why is this happening when the NHS is getting extra money?
The overall health service budget is growing at record levels - over 7% a year until 2008.
But the NHS Confederation says most of the extra cash has gone on new staff and increased salaries.
The cost of drugs has also rocketed and like the rest of the public and private sector the NHS is facing pressure over pensions.
Coupled with the most intensive period of reforms for the health service - including waiting time targets and a new system of hospital funding - NHS managers say they are struggling to keep to budget.