Geographic region and racial variations in polypharmacy in the United States.

•There is a high frequency of polypharmacy among American adults.•Polypharmacy is not equally distributed across racial groups and census regions.•Future research should investigate potential deleterious polypharmacy consequences.•However, polypharmacy is appropriate and the standard of care for some patients.•Higher Southern and white polypharmacy does not a priori indicate excessive use.