Using results from two contingent valuation surveys conducted in Canada and the United States, we explore the effect of a latency period on willingness to pay (WTP) for reduced mortality risk using both structural and reduced form approaches. We find that delaying the time at which the risk reduction occurs by 10 to 30 years significantly reduces WTP for respondents aged 40 to 60 years. Additionally, we estimate implicit discount rates equal to 8% for Canada and 4.5% for the United States-both well within the range established previously in the literature.