The year 1999 marked the beginning of reforms in social insurance in Poland. Changes which were implemented then regarded mainly retirement insurance. Until the reform was introduced, the retirement insurance had operated under a pay-as-you-go system. However, political changes in Poland, as well as adverse demographic trends, led to ineffective functioning of the existing system of financing liabilities arising from retirement insurance. It was necessary to introduce changes that, above all, would allow for maintaining an appropriate level of retirement pension. The following article concentrates on one selected aspect of this insurance - Open Pension Funds (in Polish: Otwarte Fundusze Emerytalne; OFEs) and presents major changes occurring...