How long should chicken be baked?

Temperature, not time, is what must be considered.  The oven temperature should be no lower than 325°F., and the chicken should be baked at least until it reaches an internal temperature of 165°F. This temperature will destroy salmonella, the most heat-resistant pathogen of public health concern in raw poultry.  Place a thermometer in the innermost part of the thigh and wing and in the thickest part of the breast to test for “doneness.”   
 
Keep in mind, however, that no law requires cooks to remove the chicken from the oven when the thermometer says 165°F.  Further cooking may be needed for taste and eye appeal.  To eliminate a pink appearance and rubbery texture, you may want to cook breast meat to 170° and thigh meat to 180°F. 
 
Sources:
USDA Fact Sheets "Focus On: Chicken"
 
www.fsis.usda.gov. “National Advisory Committee on Microbiological Criteria for Foods.  Response to the Questionss Posed by the Food Safety and Inspection Service Regarding Consumer Guidelines for the Safe Cooking of Poultry Products.”