CDC Division of State and Local Readiness staff were lead authors of a September 5, 2024 MMWR report, “Contact Tracing for Mpox Clade II Cases Associated with Air Travel — United States, July 2021–August 2022 .” Before 2021, limited information was available to assess mpox virus transmission risk aboard commercial aircraft. During 2021-2022, 113 persons traveled on commercial flights while they were infectious with clade II mpox. Among 1,046 traveler contacts followed by U.S. public health agencies, CDC identified no secondary cases. These findings indicate that traveling on a flight with a person with mpox does not appear to constitute an exposure risk or warrant routine contact tracing activities.