OBJECTIVES: To identify factors associated with emergency room (ER) and primary care provider (PCP) visits by members of qualified health plans (QHPs). METHODS: This study used a large nationally representative administrative claims database supplemented with neighborhood level socioeconomic data.  The sample consisted of 1,823,677 QHP members enrolled for ≥10 months in 2014. Logistic regression was used to determine factors associated with ER and PCP visits. RESULTS: A total of 15.8% of the study population members had ≥1 ER visit and 72.3% had ≥1 PCP visit. Factors associated with lower likelihood of ER visit were higher percentage of neighborhood population with bachelor’s degree or higher (ORs: 0.90-0.98; reference 0-12%); non-metropolitan area (OR: 0.72-0.90); enrolled in Bronze (OR=0.82) or Catastrophic (OR=0.9) metal level plan; and enrolled on-exchange (OR=0.96) compared to off-exchange. Factors associated with higher likelihood of ER visit were lower median household income (ORs: 1.03-1.16) or higher proportion of non-Hispanic blacks (OR=1.19) neighborhood; and enrolled in Gold (OR=1.05) or individual group plan (OR=1.08). Factors associated with lower likelihood of PCP visit were lower median household income (ORs: 0.73-0.89; reference $100,000+) or higher proportion of Hispanics (OR=0.80) or non-Hispanic blacks (OR=0.86) neighborhood; non-metropolitan area (ORs: 0.92-0.96), enrolled in Bronze (OR=0.70) or Catastrophic (OR=0.90) plan; and enrolled on-exchange (OR=0.96).  Factors associated with higher likelihood of PCP visit were higher percentage of neighborhood population with bachelor’s degree or higher (ORs: 1.03-1.07); enrolled in Gold (OR=1.09) or individual group plan (OR=1.22). CONCLUSIONS: The effects of socioeconomic characteristics on the likelihood of having an ER visit were the opposite of their effects on likelihood of having a PCP visit. However, the effects of plan characteristics on the likelihood of ER or PCP visits were in the same direction.