Background: Following a medical habilitation or equivalent qualification after continuous scientific activity, one can apply for a position as an adjunct professor (außerplanmäßige Professur). The medical faculties in Germany have issued regulations for these appointments. The aim of this paper was to compare the requirements for appointment as an adjunct professor among medical faculties. Methods: The currently valid regulations of medical faculties in Germany were analyzed for the target criteria of publication performance, teaching performance, possibility of shortening the procedure; consideration of appointment for junior professor, patents, acquisition of third-party funding, medical didactic qualifications, and/or special scientific achievements; and review procedure. Results: An analysis of 38 currently valid regulations showed large differences between the requirements. The number of required first/senior authorships differs significantly within the regulations (from 4 to 16). The median of the required number of first/senior authorships is six (Q1 = 5, Q3 = 7). In total, 93% (n = 35) of the universities provide information on the publication medium or the value of the publication. Third-party funding is desired or required in 68% (n = 26) of the regulations. There are also clear differences in the scope of required teaching activities, which range from two to a maximum of six years of teaching. Shortening the time to apply for an adjunct professorship is possible in 45% (n = 17) of the cases. In total, 97% (n = 37) of the faculties provide information on external review, with 71% (n = 27) most frequently requesting one or two external reviews. Conclusion: The regulations show clear differences among individual requirements for adjunct professorship. Standardization would be desirable and would lead to comparable conditions and therefore also to a fair recognition of scientific achievements.