The COVID-19 case surveillance system database includes patient-level data reported to U.S. states and autonomous reporting entities, including New York City and the District of Columbia (D.C.), as well as U.S. territories and states. On April 5, 2020, COVID-19 was added to the Nationally Notifiable Condition List and classified as “immediately notifiable, urgent (within 24 hours)” by a Council of State and Territorial Epidemiologists (CSTE) Interim Position Statement (Interim-20-ID-01). The statement also recommended that all states and territories enact laws to make COVID-19 reportable in their jurisdiction, and that jurisdictions conducting surveillance should submit case notifications to CDC. COVID-19 case surveillance data are collected and reported voluntarily to CDC’s COVID-19 Response.

These deidentified data include demographic characteristics, exposure history, disease severity indicators and outcomes, clinical data, laboratory diagnostic test results, and comorbidities. All data elements can be found on the COVID-19 case report form located at www.cdc.gov/coronavirus/2019-ncov/downloads/pui-form.pdf

The Case Surveillance Task Force and Surveillance Review and Response Group (SRRG) within CDC’s COVID-19 Response provide stewardship for datasets that support the public health community’s access to COVID-19 data while protecting patient privacy.

COVID-19 case reports have been routinely submitted using standardized case reporting forms. On April 5, 2020, CSTE released an Interim Position Statement with national surveillance case definitions for COVID-19 included. Current versions of these case definitions are available here: https://wwwn.cdc.gov/nndss/conditions/coronavirus-disease-2019-covid-19/ . All cases reported on or after were requested to be reported by public health departments to CDC using the standardized case definitions for lab-confirmed or probable cases. On May 5, 2020, the standardized case reporting form was revised. Implementation of case reporting using this new form is ongoing among U.S. states and territories.

The COVID-19 case surveillance data are dynamic; case reports can be modified at any time by the reporting jurisdiction as new information becomes available (i.e., data are subject to change). Furthermore, reporting jurisdictions may report cases late. Version updates to the detailed and limited datasets will be available for request once a month.The datasets will include all cases with an initial report date of case to CDC at least 14 days prior to the creation of the previously updated datasets. This 14 day lag will allow case reporting to be stabilized and ensure that time-dependent outcome data, including death, are accurately captured.

CDC’s Case Surveillance Task Force routinely performs data quality assurance procedures (i.e., ongoing corrections and logic checks to address data errors). To date, the following data cleaning steps have been implemented:Questions that have been left unanswered (blank) on the case report form are re-classified to a Missing value, if applicable to the question. For example, in the question “Was the patient hospitalized?”, where the possible answer choices include “Yes”, “No”, or “Unknown”, the missing value is re-coded to Missing if the respondent did not answer the question.Logic checks are performed for date data. If an illogical date has been provided, CDC reviews the data with the reporting jurisdiction. For example, if a symptom onset date that is in the future is reported to CDC, this value is set to null until the reporting jurisdiction updates this information appropriately.The initial report date of the case to CDC is intended to be completed by the reporting jurisdiction when data are submitted. If blank, this variable is completed using the date