The CLSA's Data Collection Sites are located in Victoria, Vancouver, Surrey, Calgary, Winnipeg, Hamilton, Ottawa, Montréal, Sherbrooke, Halifax and St. John's.

Participants who take part in in-home interviews and visit a DCS have agreed to be part of the comprehensive assessment within the CLSA. Once every three years, CLSA interviewers visit participants in their homes to conduct face-to-face interviews and schedule their visit to a DCS. At the DCS, participants are asked to undergo additional data collection, including questionnaires,  and cognitive and physical assessments. Blood and urine samples are also collected (with participant consent) at the DCS.