MMP is a supplemental HIV surveillance system, funded by the Centers for Disease Control and Prevention (CDC), designed to produce nationally representative estimates of behavioral and clinical characteristics of HIV-infected adults receiving medical care in the United States (McNaghten, Wolfe et al. 2007; Blair, McNaghten et al. 2011; Frankel, McNaghten et al. 2012). MMP is a complex-sample, cross-sectional survey.