The National Union of Teachers and other teaching unions have brought thousands of claims on behalf of part-time and short-term contract members, alleging that their exclusion from the Teacher's Pension Scheme was unlawful.
The DFES and other government agencies have defended the claims, despite rulings by the European Court of Justice and the House of Lords which allowed some of the cases to proceed.
Now the DFEShas told the NUT it will no longer deny that the exclusion of part-time and hourly-paid teachers was discriminatory and could not be justified.
Teachers who were denied entitlement to a pension, despite many years of service in some cases, will now be ble to claim backdated admission to the scheme - without going to an employment tribunal.
Up to 3,000 teachers could receive backdated pensions. A teacher with 25 years' service who was part-time for 12 years and retired on a salary of pound;24,000, could gain pound;1,800 in annual pension and a pound;5,400 lump sum.
However, the DFES and the unions are still arguing about whether teachers needed to have made a compensation claim within six months of retiring.
They also dispute whether some part-time and short-term work qualifies as continuous employment.
Amanda Brown, NUT legal officer, said: "We are delighted that the DFES has accepted that the rules did discriminate."
ADFESspokesman said:"We should be able to start retrospective scheme membership for eligible teachers from the autumn."