In January 2016 people became ill following a catered holiday meal held at a private home. The implicated meal date was January 8, 2016. Six people reported symptoms of vomiting and/or diarrhea. The median incubation period was 24 hours (range, 12 to 48 hours). Based on symptoms, incubation and duration, public health investigators in Lake County, Colorado concluded this was an outbreak of norovirus. No one was hospitalized and no one died.