The book deals with the reasons for the admission of appeals as a prerequisite for access to the five highest federal courts (Federal Court of Justice, Federal Administrative Court, Federal Finance Court, Federal Labor Court, and Federal Social Court). Despite the now uniform access regulation through admission appeals, there are still significant differences in the legal regulation of the grounds for admission and their interpretation by the highest federal courts, alongside some commonalities. The author examines and evaluates these similarities and differences and concludes the study with a proposal for a uniform regulation and interpretation.