Contact Tracing

Get and Keep America Open: Supporting states, tribes, localities, and territories

Revisions were made on May 29, 2020 to Health Departments: Interim guidance on developing a COVID-19 case investigation & contact tracing plan to reflect the following:

The contact elicitation window for asymptomatic cases was changed from 10 days before obtaining the specimen that tested positive for COVID-19 to 2 days to accommodate pragmatic and operational considerations for the implementation of case investigation and contact tracing programs.  Additionally, recent data suggests that asymptomatic persons may have a lower viral burden at diagnosis compared to symptomatic cases.  Thus, the longer contact elicitation window (beginning 10 days prior to specimen collection) may have limited impact in identification of new COVID-19 cases.  Furthermore, the recommendation for the shorter contact elicitation window (beginning 2 days prior to specimen collection) will help focus case investigation and contact tracing resources towards activities most likely to interrupt ongoing transmission. This time period is also now in alignment with WHO, European CDC, and Public Health Canada.

Summary of Recent Changes

Revisions were made on May 22, 2020, to reflect the following:

Revisions were made on May 15, 2020, to reflect the following:

CDC guidance for COVID-19 may be adapted by state and local health departments to respond to rapidly changing local circumstances.

Key Concepts

  • Trace and monitor contacts of infected people. Notify them of their exposure.
  • Support the quarantine of contacts. Help ensure the safe, sustainable and effective quarantine of contacts to prevent additional transmission.
  • Expand staffing resources. Contact tracing in the US will require that states, tribes, localities and territorial establish large cadres of contact tracers.
  • Use digital tools. Adoption and evaluation of digital tools may expand reach and efficacy of contact tracers.

Resources from CDC

Resources for conducting contact tracing to stop the spread of COVID-19

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Digital Tools


How COVID-19 Can Spread in a Community

Resources from Other Organizations

Content describing non-CDC tools on this site is provided for informational purposes only and is not intended to indicate endorsement, actual or implied, of the tools. Additionally, information on this site is provided “as is,” for users to evaluate and make their own determination as to their effectiveness.

Other Federal Agencies

Several other federal agencies are also supporting this critical effort by providing:

Private Sector, Non-governmental Organizations and Academia

Various other organizations are also supporting this critical effort by providing:

Digital Tools



  • National Network of Public Health Institutes: NNPHIexternal icon mobilizes more than 45 member public health institutes with as well as 10 university-based regional training centers serving all ten HHS regions. Find training or join an online community to connect with public health practitioners about COVID response, recovery, and related issues like workforce resilience.
  • Association of State and Territorial Health Officials/National Coalition of STD Directors: Making Contact: A Training for COVID-19 Contact Tracersexternal icon. An introductory online course for entry-level COVID-19 contact tracers, for use by health agencies in rapid training of new contact tracers. The training should be augmented by state/local specific training required to orient individuals to jurisdiction-specific protocols.
  • ASPPH Curated List of COVID-19 Related Training Coursesexternal icon