IRP 2 was implemented in July 2014, as explained on the short history of MSF's International Remuneration System on the homepage.  All staff who joined MSF after 1 July 2014 are automatically rewarded according to this system (IRP 2).  

For staff who started before July 2014 and continue to go on assignments with MSF, special measures were put in place to guide the transition to the new system. According to these measures, in the cases where the salary in the IRP2 system would be less than their last salary under the old system (IRP 1), the salary the international staff is maintained at the previous (IRP 1) level, in the following cases:

- Provided that the position occupied in the new assignment is at least at the same level as the position last occupied under the old system (which would be the reference salary).

- If the break in service (time since the assignment), was less than 12 months (or 24 months if the period is spent working as national staff in the field or in one of MSF's HQ offices).

If the position the international staff takes in the new IRP 2 system is lower than the last position worked in the IRP 1 system, then MSF refers to the equivalent salary for that lower level position in the old system (IRP 1). This salary is applied if it is still higher than the salary in the IRP2 system.
 
Staff members concerned are still eligible for the benefits and contracts offered through IRP 2, with one limit concerning the Home Child Allowance (HCA) for Long Term assignments (LTAs) and Vocationers.

A Home Child Allowance does not come on top of an already protected salary. When comparing the last IRP 1 salary to the new IRP 2 salary plus HCA amount, if the total (IRP 2 salary + HCA) is higher that the last salary under the old system (IRP 1), then the person receives the new IRP 2 + HCA amount for the duration of the LTA or Vocationer contract concerned.  For subsequent assignments, if you are no longer eligible for the HCA  (e.g. dependents turn 18 or the initial contract/duration of assignment is shorter than 12 months), MSF returns to using the last IRP 1 salary as a reference, and the international staff member continues being "protected" if relevant (i.e. paid the last IRP 1 salary if the new IRP 2 salary is lower), provided they were not out of the field for more than 12 months.