When you change jobs, your pension fund membership fund may also change. Many collective wage agreements or employment contracts provide for membership in a particular pension fund. If there is no such provision, then you are entitled to choose your own pension fund, insofar as the rules of that pension fund allow.
This, however, does not apply to private pension savings, which are the responsibility of each individual. You will, therefore, need to contact the depository to ensure that the private pension savings plan is transferred between employers. It is extremely important to ensure that payments continue to be deposited in the private pension plan, as this is one of the most advantageous savings methods and is, in fact, the equivalent of a 2% wage increase due to the matching contribution of the employer.
If you have not already begun saving in a private pension plan, then it would be prudent to begin doing so as soon as possible.