Public sector employees who do voluntary work in some of the world's poorest countries will still receive pension contributions.
Workers such as doctors, nurses, the police and teachers who work with disadvantaged people in developing countries currently miss out on pension contributions while they are abroad.
But the Government has said it has created a £13 million fund to continue making pension contributions while public sector employees are abroad.
It is hoped the move, which forms part of the Government's response to Lord Crisp's report into improving links between health services in the UK and developing countries, will encourage more public sector workers to volunteer.
The new fund is being supported by the Departments of Health, International Development and Children Schools and Families.
It will be available to people leaving the UK between April 2008 and March 2011 for periods of between seven and 24 months.
Pension contributions will be based on people's salaries before they leave the UK, and will be paid once they return to public sector employment.
International Development Secretary Douglas Alexander said: "Volunteering brings vital skills and energy to our efforts to tackle poverty in the developing world.
"And now the Government is providing more support and encouragement for those who have skills to share.
"Volunteering plays a valuable role in our society, not just in helping to reduce global poverty, but in the wealth of experience volunteers will bring back to the UK and into public service."
