In order to ensure pension schemes remain affordable, those who joined up between 1975 and 2005 could see the pension age rise to 60, in a development that would launch in 2015. However, service personnel will not have to contribute personally and will get a lump sum if they leave after the age of 40 with the required years of service.
Those who joined the forces after April 2005 already have to claim their pensions at 60. Those who joined between 1975 and 2005 have always been able to claim their pension at aged 55.
A spokeswoman for the MoD said that only 2% of those who serve in the Armed Forces do so until age 55. And the MoD insists those in uniform will still have better terms than most other public sector workers. If the new pension age becomes 60, it will still be lower than other public service pensions - linked to the state pension age - which is considerably higher.
Minister for Defence Personnel, Welfare and Veterans, Andrew Robathan, said: "The government has had to make some tough decisions to ensure sustainable public service pensions which provide a fair deal for both service personnel and for the taxpayer.
"We recognise the unique commitment made by the Armed Forces and we have done all we can to protect them and make these changes in the fairest way possible.
"The proposed new scheme will remain among the very best available in the public or private sector, with no individual contributions required by service personnel."
The MoD says the reforms were conceived after consultation with more than 17,500 personnel in the UK and overseas. It has promised to consult further before bringing the changes into force