The NHS in England has to look abroad for new ideas - or face a large funding shortfall by the start of the next decade, a health regulator has said.
Monitor said the NHS was only likely to reach two-thirds of its £30bn saving target by 2021 if it kept on as it was.
Most savings so far have come from keeping wages low and improving productivity.
But the regulator said the NHS should be more radical by borrowing ideas from countries such as India and Mexico.
Monitor's report cites Aravind Eye Care which runs a network of cataract clinics across India.
The report said: "By streamlining the workflow of care to maximise the use of staff skills, Aravind is able to perform 60% of the number of NHS cataract surgeries but at one-sixth of the cost to the NHS and achieve better clinical outcomes."
Another scheme highlighted was Medicall Home in Mexico which is a nurse telephone advice service that has had great success in reducing the need for consultations with local doctors.
"If the NHS were to introduce a similar service and it reduced 50% of first visits to general practice, where patients would otherwise have seen a doctor, we estimate it could free up GP time worth in the region of £0.6bn to £0.8bn, taking into account the cost of nurses to run the phone service," stated the report.
Other schemes highlighted include one in Ghana for capturing patient information and images on a mobile phone and sending them "for interpretation by a doctor at a different location".
Monitor said using fresh ideas such as these could help the NHS meet its ambitious savings targets.
Over recent years the NHS has been working towards saving £15-20bn by 2015 - the so-called "Nicholson challenge".
But it is now becoming accepted that the savings drive will need to be extended beyond that and hence a £30bn figure has been put forward for 2021.
'Freedom to innovate'
Monitor chief executive David Bennett said he agreed with that but claimed the combination of wage restraint, productivity improvements and reconfiguration of hospitals services was only likely to save around two-thirds of that and so fresh ideas were needed.
He said that could either be achieved by getting new providers from abroad into the NHS to compete or by getting NHS trusts to adopt their ideas.
He added: "We are not going to make the numbers add up if we don't have this sort of innovation.
"We must not rule out letting players outside the NHS from coming in and showing us how to do things differently."
British Medical Association leader Dr Mark Porter questioned how easy it would be to adopt ideas from abroad.
"Doctors would need to see more detail as to how the changes proposed would work in reality," he said.
But he added it was clear the continuing funding crisis meant doctors had to be given the "freedom" to innovate.
Monitor, set up in 2004, describes itself as "the sector regulator for health services in England". It exercises a range of regulatory powers under different acts of parliament.