Doctors' skills are to be reassessed every year to ensure they are fit to practise, Health Secretary Jeremy Hunt has announced.
At present, doctors can go for their entire career without facing any formal assessment of their competency.
But from December this year, doctors will be assessed to see if they are fit to stay on the medical register, he said.
The General Medical Council (GMC) said the move was the "biggest change" in medical regulation for 150 years. The new system will mean that problems with doctors are flagged earlier, said the GMC.
The assessment will take the form of an annual appraisal and a more comprehensive meeting every five years. Doctors will be expected to demonstrate they meet clinical standards and have kept up to speed with the latest developments in their field. Appraisals will include feedback from patients and colleagues.
Mr Hunt said: "We want to have the best survival rates in Europe for the major killer diseases. Doctors save lives every day and making sure they are up to speed with the latest treatments and technologies will help them save even more. This is why a proper system of revalidation is so important."
All doctors in the UK with a licence to practise will be linked to a "designated body" which will be responsible for conducting the appraisal. Every five years a "responsible officer" - who is in charge of the appraisals - will send a recommendation to the GMC on whether each doctor should be revalidated.
"This is an historic moment, it is the biggest change in medical regulation for more than 150 years," said Niall Dickson, chief executive of the GMC. But he warned: "Revalidation is not a panacea, it is not a magic bullet to guarantee that care is safe or that every doctor is perfect. It will take time to settle in."
NHS medical director Professor Sir Bruce Keogh admitted that implementation will be "initially quite difficult" and that the system would not be immediately perfect, but added: "My personal view is that it is better to start than wait for perfection."
The process will start in December with the revalidation of medical leaders and from April next year it will start to assess mainstream doctors. By April next year every doctor will have been told when their revalidation is due. By 2014, 20% will have been revalidated and the "vast majority" will have been through the process by April 2016.