Background . Insufficient information on SARS-CoV-2 testing results exists in clinical practice from the United States . Methods . We conducted an observational retrospective cohort study using Optum (R) de-identified COVID-19 electronic health records from the United States to characterize patients who received a SARS-CoV-2 viral or antibody test between February 20 , 2020 and July 10 , 2020 . We assessed temporal trends in testing and positivity by demographic and clinical characteristics; evaluated concordance between viral and antibody tests; and identified factors associated with positivity via multivariable logistic regression . Results . Our study population included 891,754 patients . Overall positivity rate for SARS-CoV-2 was 9% and 12% for viral and antibody tests, respectively . Positivity rate was inversely associated with the number of individuals tested and decreased over time across regions and race/ethnicities . Among patients who received a viral test followed by an antibody test, concordance ranged from 90% -93% depending on the duration between the two tests which is notable given uncertainties related to specific viral and antibody test characteristics . The following factors increased the odds of viral and antibody positivity in multivariable models: male, Hispanic or non-Hispanic Black and Asian, uninsured or Medicaid insurance, Northeast residence, dementia, diabetes, and obesity . Charlson Comorbidity Index was negatively associated with test positivity . We identified symptoms that were positively associated with test positivity, as well as, commonly co-occurring symptoms / conditions . Pediatric patients had reduced odds of a positive viral test, but conversely had increased odds of a positive antibody test . Conclusions . This study identified sociodemographic and clinical factors associated with SARS-CoV-2 testing and positivity within routine clinical practice from the United States.