This study concerns the legal aspects of increasing the retirement age in Poland. It adopts the assumption that from a legal point of view raising the retirement age is changing the scope of using the legal norm as the basis for entitlement to a pension, or change in legal classification of the effects of past events relevant to the rights acquired or purchased. According to the author, such a change as constituting a potential object of particular protection of legal classification of these events should be assessed from the point of view of development rights derived from the rule of democratic state of law. The article therefore attempts to evaluate the legal regulation of increasing the retirement age in the context of its impact on situations of the insured with are shaped by the current legal regime. This area of study focuses on determining whether the new regulations interfere with the social position of the insured shaped to such an extent that in the light of the Constitutional Court and the views of doctrine may be subject of protection under the principle of acquired rights. The remainder of this paper assesses the changes from the point of view that the principle of citizens’ trust in the state and its laws is maintained and respect that the requirement for nonarbitrariness for the adoption of criteria for changing the law. The article closes with more general observations about the importance of the decision about increasing the retirement age for the assessment of the implementation of postulate of entirely of employees insurance. In this regard, the article also includes general observations regarding the location of the new benefits, which is a partial pension, in the system of social security benefits, defined as benefits compensating the effects of disability or inability of its provision (social risk).