People off sick for more than four weeks are to be offered advice to get them back to work more quickly under a scheme being set up by the government.
The Health and Work Service, which will cover England, Wales and Scotland, will offer non-compulsory medical assessments and treatment plans.
It will be run by the private sector and paid for by scrapping compensation to employers for statutory sick pay.
Ministers say employers will save money overall by having fewer staff off sick.
They said it may save companies up to £70m a year in reduced sickness pay and related costs.
Labour's shadow work and pensions minister, Kate Green, said: "Any help to cut number of days lost to sickness is welcome, but with the government's Work Programme helping just 5% of people on sickness and disability benefits into jobs, it is clear much more needs to done to help people get back to work."
No law change
The new scheme will not entail any change to existing laws.
At present, staff who are off work for more than four weeks are considered to be long-term sick and entitled to Statutory Sick Pay of almost £90 per week from their employers.
That will not change under the new arrangements - but the government wants the Health and Work Service to cut the number of people on long-term sick leave.
Under the scheme, employers or GPs will be able to refer employees for a work-focused occupational health assessment.
This is intended to identify the issues preventing an employee from returning to work and draw up a plan for them, their GP and their employer, recommending how the employee can be helped back to work more quickly.
This may include fitness for work advice, medical care, working from home or retraining.
The scheme is not compulsory. Workers will be allowed to refuse to be assessed or to follow any course of action or treatment recommended.
The Department for Work and Pensions (DWP) says it is intended that the service will start operating this year.
It will be run by the private sector, with the firms managing it decided by a tendering process.
The service will be paid for by scrapping the Statutory Sick Pay Percentage Threshold Scheme (PTS), which gives some compensation to employers faced with high levels of sickness absence.
The government says PTS is "an outdated system which does nothing to promote or support active management of sickness absences by either the employer or employee".
Minister for Disabled People Mike Penning rejected suggestions that ending PTS was about the government saving money.
He said the compensation to employers under PTS amounted to only £10 a week on average for each employee.
"We think we can use that money much better," he said.
In return for losing that compensation employers would instead have access to an occupational health scheme.
He said employers should regard that as "a good investment".
The financial loss to business from ending PTS would also be offset by a reduction in lost working days, earlier return to work and increased economic output created by the new scheme, the DWP said.
It said small businesses, which do not generally have occupational health services, would particularly benefit.
Mr Penning said sickness absence had a "substantial impact" on workers, employers and taxpayers.
"As part of the government's long-term economic plan, we are taking action to get people back into work," he said.
"This is a triple-win. It will mean more people with a job, reduced cost for business, and a more financially secure future for Britain."
The Trades Union Congress said it supported anything that could help people get back to work when they are ill, and that being in a rewarding job with a supportive employer could be good for your health.
But it said care should be taken over how the scheme was implemented.
The TUC's head of health and safety, Hugh Robertson, said: "The focus of this service should be about getting them [workers] better as opposed to just back to work and the two are not necessarily the same."
The danger was that people would be forced back to work before they were well.
Mr Robertson added: "Also there is nothing which can force employers to do anything with the advice they are given [by occupational health experts]."
Pensions Minister Steve Webb denied that people would be forced back to work prematurely.
He said: "It is about sitting down and supporting people, saying What help and support do you need to make sure this sickness absence is not any longer than it needs to be."
About one million people in Britain are off work long-term because of illness, according to the government.
The rate of absence through sickness is among the lowest in Europe and has halved over the past decade.