This question must have already passed by your head. With passing time, it can be coming more often. 

Here is some basic information. 

Let’s start with legal bases.
The current provisions you can find in Art. 77 to 85a of the staff regulations plus in annex VIII of the Staff Regulations, plus in annex XIII: transitional measures applicable to officials of the European institutions as well as in Conditions of employment of other servants (C.E.O.S). 

Feeling that you might not really grasp it after reading the text? Here are some further explanations with examples.

Each month 10.1% of your gross salary is taken to a virtual fund i.e. commission budget. There is no real fund (oh yes). Your future pension is based on a solidary MS obligation to pay it to you in the future. 

To be eligible you will have worked at least 10 years in the institutions (except if your retirement age falls before 10 years period). If you did not cumulate 10 years of service, you pension fund will be transferred out to a selected private pension fund. 

When can you retire? 

The normal pension age will depend on your age and date when you joined the institutions. 

• If you were recruited before 1/5/2004, you will be able to retire officially between 60 and 65, but since the condition was to have 20 years of service at 01/05/2004 to retire at 60, you will have to calculate it based on your age on 01/05/2014 with 65 years as a maximum (see table in annex art 13 annex XIII).
  For example:  if you were 40 on 01/05/2014 your pensionable age will be 63 years and 10 months, if you were 50 your pensionable age will be 61 years and 11 months.

• If you are less lucky and were recruited between 1/5/2004 and 31/12/2013 you will be able to retire between 63 and 65. The same table applies as in the previous case, with a change that if you were 45 or more on. your pensionable age will be fixed at 63, if younger you will have to add 2 months per year of your age.
  For example:  if you were 40 on 01/05/2014 your pensionable age will be 63 years and 10 months (as in the previous case), if you were 50 your pensionable age will be 63.

• If you are the least lucky and were recruited after 01/01/2014 the normal pension age is 66.
  

Now, the SR envisages early retirement with as of age of 58, minimum 10 years of service, however this solution will come at a cost: 

• If you were recruited before 01/01/2014
  -3.5 %/year, but only half this reduction 
  -1.75%/year between the age of 60 and the normal pension age  
• If you were recruited after 01/01/2014
  -3.5 %/year
  Attention for traps, there are no fractions! for example:
  
  If your normal retirement age= 62 years and 2 months 

• • You want to retire at 60 years and 2 months: reduction will be: 2 x 1.75% = 3.5
  • You want to retire at 60 years and 1 month: reduction will be: 3 x 1.75% = 5.25% 

Below you will find an example how to calculate reduction in your pension if you decided to retire at the age of 58 

• You were recruited before 1/1/2014
  Normal pension age: 64 years
  Beginning of pension: 58 years
  Reduction: (2 x 3.5 %) +(4 x 1.75 %) = 14 %
  If acquired rights at 58 = 25 %
  Reduced rights = 25 % – 3.5% (14 % of 25 %) = 21,5 %
   
• You were recruited after 01/01/2014 
  Normal pension age: 66 years
  Beginning of pension: 58 years
  Reduction: 8 x 3.5 = 28 %
  If acquired rights at 58 = 25 %
  Reduced rights = 25 % – 7% (28 % of 25 %) = 18 % 

If you cannot live without work you can ask for extension of your active status after your pensionable age till 67 and in exceptional cases to 70. Your loyal services in such case will be awarded with extra 1.5% per year and 2.5% if recruited before 1/1/2014.