This paper seeks to examine the impact of postgraduate non-degree programs undertaken by the employed in Poland on the level of their earnings in the main job. From a theoretical point of view, we can expect a positive impact of this kind of investment in human capital on the situation of individuals in the labor market. We conducted a short-run analysis using the Difference-in-Differences Propensity Score Matching (DID-PSM) method and data from the Polish Labor Force Survey (PLFS) for 2001–2013. The analysis shows that postgraduate programs had a positive impact on earnings only in 2009–2013. However, positive wage effects were also observed for the whole analyzed period for selected groups of graduates, specifically women and those employed in the public sector. Other than that postgraduate programs had no impact on the hourly earnings rate in the study period.