Project Summary / Abstract Health policies, educational programming, and health-related services require accurate and up- to-date data on the sexual behaviors, attitudes, and experiences of the population. We propose to conduct Wave 8 of the National Survey of Sexual Health and Behavior (NSSHB) in order to support such public health efforts. Sexual health is an important part of human health. Since 2014, sexually transmitted infection (STI) rates have increased annually. STIs challenge the health of individuals and newborns, and cost billions of dollars each year. Unintended pregnancies have decreased overall, though adolescent and young adult women are at greater risk for unintended pregnancy as are sexual minority women. Among adolescents aged 15-19, 3 of 4 pregnancies are unintended. Sexual health has been conceptualized by the World Health Organization (WHO) as a state of physical, emotional, mental and social well-being in relation to sexuality; it refers not only to the absence of disease but also to the possibility of pleasurable and safe sexual experiences that are free of coercion, discrimination, and violence. From adolescence through old age, people have diverse sexual health needs. These sexual health needs include choosing when to become sexually active with a partner, preventing unintended pregnancy, reducing risks of HIV and sexually transmitted infection (STI), accessing and using condoms/contraception, sexual identity development, patient/provider sexual health conversations, painful sex, vaginal dryness, sexual coercion and assault, sexual function, as well as the development and maintenance of satisfying relationships. Since 2009, the NSSHB has served as the nation's only U.S. nationally representative probability survey that is focused on sexual health, assesses diverse sexual behaviors and attitudes, and samples individuals from adolescence through advanced age (often ages 14 to 94). We have a unique opportunity to develop the NSSHB-Wave 8 so as to maximize cross-national comparisons with other nationally representative probability surveys of sexual health being conducted in a similar time frame in the U.K., France, and Australia. We aim to: (1) Design and field NSSHB-Wave 8, surveying 9500+ individuals; (2) Demonstrate the scientific and public health importance of NSSHB-Wave 8 by updating population-prevalence of sexual health behaviors, establishing the population-prevalence of understudied sexual behaviors, and examining associations between certain sexual behaviors and reproductive coercion and sexual coercion; and (3) work closely with an Advisory Board of sexual and reproductive health scientists, educators, and key leaders to disseminate findings and to facilitate data availability to other scientists.