In September 2016, local, state, and federal agencies investigated an outbreak of Salmonella infections linked to consumption of rotisserie chicken salad purchased at the Costco Warehouse located at 18109 33rd Avenue West in Lynnwood, Washington. Among Washington residents, 3 persons were laboratory confirmed with Salmonella serotype I, 4,[5],12:i:-. A fourth ill person was a family member epidemiologically linked to illness in his/her spouse. Purchase dates ranged from August 26 to September 9. Onset of illness ranged from September 2 to September 6.