In the year 2012 it was decided to increase retirement age in Poland up to 67 year. Part of that regulation was new institution – partial old age benefit for insured below the new retirement age. Partial old age benefit was introduced for insured in ‘common’ system (for employees) as well as in peasants separate system. However regulations related to partial old age benefits in both systems are different. In case of peasants system, the partial old age benefit is equal 50% of the old age benefit due in the retirement age and the payment of the old age benefit has no influence into the level of the old age benefit due in the retirement age, while in case of ‘common’ system the partial old age benefit is lower than 50% of the old age benefit due in the retirement age, as only part of the sources taken into consideration to calculate the old age benefit is taken into consideration (assets saved in open pension funds and contributions registered on special subaccount in Social Security Institute are omitted), as well as the payment of the partial old age benefit reduces the level of the old age benefit due in the retirement age. As there are significant differences between ‘common’ (Defined Contribution, PAYG and capitalized) system and peasants one (Defined Benefit, PAYG), there is no reason for creating incentives to use partial old age benefit in peasants system and the same time disincentives in ‘common’ system. Based on that consideration it is justified to claim that the regulations related to partial old age benefit are not in line with constitutional rule of democratic state ruled by law and guaranties of equality before the law. As there is vacatio legis period up to 1st January 2013, there is still time for corrections.