title: Solo practitioners remain important contributors to primary care.
authors.affiliation: From Mathematica Policy Research, Princeton, NJ. dpeikes@mathematica-mpr.com.
authors.forename: Deborah N
authors.initials: DN
authors.lastname: Peikes
authors.affiliation: From Mathematica Policy Research, Princeton, NJ.
authors.forename: Stacy Berg
authors.initials: SB
authors.lastname: Dale
mesh_terms: D006801:Humans; D010821:Physicians, Family / Q000639:trends*; D011331:Private Practice / Q000639:trends*