South Yorkshire and Bassetlaw was one of 14 areas of the country given permission to form an Integrated Care System (ICS), which involves councils, NHS organisations and the voluntary sector.
The ICS, designed to meet rising demand from patients and address a multi-million pound budget shortfall, has officially taken greater control of services in Barnsley, Bassetlaw, Doncaster, Rotherham and Sheffield.
NHS campaigners have claimed that the ICS system will be used to make cuts to services and will make it easier for private companies to bid for contracts.
But health bosses say it will improve services as different organisations work more closely together.
Sir Andrew Cash, Chief Executive of South Yorkshire and Bassetlaw ICS, said: “It is an exciting time for us in South Yorkshire and Bassetlaw.
“There is commitment in our places for coming together to break down barriers between services so people experience more seamless and co-ordinated care from across our public services and the voluntary sector.
“We will look at what we do well and what could be done better to ensure that we are supporting people to start life well, live well and deliver the best possible care and support to people.”
The launch of Integrated Care Systems followed a radical review of services nationally in 2016.
Health and social care organisations in 44 areas of England were required to form Sustainability and Transformation Partnerships (STPs) to set out how services would be run over the following five years. At the time, the NHS was facing a £22bn budget shortfall.
The funding gap in South Yorkshire and Bassetlaw was £571m by 2021.
Some areas were then given the go-ahead for the formation of Integrated Care Systems.
Nora Everitt, of South Yorkshire and Bassetlaw NHS Action Group (SYBNAG), said: “The initial reason given for it was to save £571m that would normally be spent in the five years if no changes were made.
“There should not be cuts to the budget to do the NHS on the cheap. That is not going to improve services. It seems to be about saving money and dealing with a lack of staff rather than investing.
“It also opens the door to contracting outside of public bodies.”
NHS bosses said the South Yorkshire and Bassetlaw ICS had been allocated £25m of new funding in 2018/19 to improve services.
In June, Prime Minister Theresa May announced an NHS funding increase which amounts to around £20bn a year by 2023.