Devolution has led to four "different" health systems operating in the UK, according to the head of a charity which represents NHS organisations.
Dr Gill Morgan, the chief executive of the NHS Confederation, said services now differ between England, Scotland, Wales and Northern Ireland.
She told the BBC: "We basically have four different systems albeit with the same set of values.
"This period [since devolution] has been unique in the history of the NHS as it was essentially the same across the UK before devolution. We have had a complete split in philosophy."
She said trusts in England have tried to reduce waiting times and are now offering patients more choice, but waits in Scotland have been less of a priority as free personal care is offered in the country, unlike the means-tested systems elsewhere.
Wales, meanwhile, has introduced free prescriptions, while Northern Ireland has seen more integration between health and social care, she added.
Dr Morgan said it is too soon to assess which method will be the most beneficial for patient care as each has its advantages, but she stressed the differences will become even greater over time.
The NHS Confederation includes all types of statutory NHS organisations and independent providers of NHS services, and aims to influence Government policy and promote excellence.