The Medical Reserve Corps (MRC) is a key strategy used in the United States to assure an adequate surge capacity healthcare workforce for response to disasters. A survey of Hawaiian healthcare providers (n = 1,057) was conducted to identify factors that influence interest, ability, and willingness to join the MRC; 468 (44.3%) healthcare providers responded. Overall, females were more likely to demonstrate an interest in joining the MRC, while physicians and dentists reported lower levels of ability and willingness, in addition to a lower level of interest in joining the MRC than the other professional groups. The most important motivating factor in joining the MRC was altruism and the ability to help one's own community. Respondents reported a number of factors that would influence their decision to join or remain a MRC member. These included: (1) time commitment required; (2) MRC organization and management; (3) provision of MRC-sponsored training or education sessions and continuing education credits; (4) concerns regarding the safety of family members during a disaster; (5) professional liability protection for work performed during MRC operations; and (6) competing personal obligations. Strategies targeting these factors probably will be most effective in recruitment and retention of MRC volunteers as well as members of other public health surge capacity volunteer groups.