Representation and inclusion are stated priorities for many scientific and professional organizations, including the Society for Epidemiologic Research (SER), which was founded in 1967 with the intention of bringing together epidemiologists across career stages and specialties. Representation and inclusion are necessary for fostering safe and equitable educational and professional environments, recruiting future generations of researchers and practitioners, and addressing critical public health questions. However, there has been persistent underrepresentation and systemic exclusion of marginalized groups in the sciences, including epidemiology which are symptoms of interpersonal and structural racism, classism, sexism, ableism, heteronormativity, religious-based discrimination, and other dimensions of marginalization. To advance SER’s goals, the Diversity and Inclusion Committee has sought to characterize representation and inclusion among SER members and affiliates through surveys conducted in 2018 and 2021. In this study, we assessed trends in representation within SER, made comparisons with relevant benchmarks, and discussed barriers to inclusion. In the 2018 baseline survey, many groups were underrepresented relative to the US population, particularly transgender individuals, Black/African American and Hispanic/Latinx people, and first-generation college students. Moreover, women and people with certain racial/ethnic and religious identities were less likely to participate in SER activities or to report feeling welcomed. This letter provides primary findings from an updated assessment of representation and inclusion among SER members and affiliates and situates the experiences of SER members in broader literatures on diversity and inclusion. The complete report, including a more detailed discussion of recommendations informed in part by survey respondents, is available on the SER website and eScholarship Repository.