Declining survey response rates concern researchers aiming to ensure study validity. This article tested the effectiveness of multiple pre-incentives on increasing survey response to the Millennium Cohort Study. Participants consisted of U.S. military service members and veterans, and were randomly assigned to receive a $2 bill, $5 gift card, magnet, Apple iPad® lottery entry, or no pre-incentive. Participants who received the gift card or cash pre-incentive had the highest response rates and were significantly more likely to respond to the survey than those who did not receive a pre-incentive. There was no significant difference in survey response among the magnet or lottery entry groups compared to the no pre-incentive group. This study found that giving participants a monetary pre-incentive was an effective way to increase response rates, and thereby participant retention, in a hard-to-reach, highly mobile population, and re-engage participants who did not respond to a previous follow-up survey.