An approach is provided for generating navigation guidance for incomplete maps. The approach, for example, involves calculating, by a processor, a confidence level of one or more links of the navigation route based on a completeness of map data in an area including the navigation route. The approach also involves determining a specificity level of a navigation guidance command based on the confidence level. The approach further involves generating the navigation guidance command at the determined specificity level. The approach further involves presenting the navigation guidance command in a user interface of a navigation device.