An ambulatory infusing device including a housing, a reservoir defining an interior volume, a wall associated with the housing and having an inner surface that faces into the reservoir interior volume, and a filter assembly. The filter assembly may include a filter assembly housing with a housing filter portion having a free end associated with the inner surface of the wall and a filter supporting volume that extends to the free end of the housing filter portion, and a filter located within the filter supporting volume that extends to at least the free end of the housing filter portion.