Introduction: Disease-risk genetic testing plays a central role in precision medicine by enabling early detection, prevention, and individualized treatment. This dissertation aims to quantify awareness and utilization of disease-risk genetic testing and post-test behaviors, including result sharing and health-related changes and to examine factors contributing to disparities across racial and ethnic groups Methods: Data were drawn from the 2022 Health Information National Trends Survey (HINTS 2022), a cross-sectional, national survey of U.S. adults. Survey-weighted descriptive and multivariable logistic regression analyses were conducted to identify disparities and influential factors in awareness, utilization, and post-test behaviors of disease-risk genetic testing. The analysis was further stratified by racial/ethnic groups to examine subgroup-specific determinants. Results: A total of 52.6% of respondents reported awareness of disease-risk genetic testing, while 14.3% reported test use. Among the users, 57.9% shared results with healthcare providers or genetic counselors, 61.4% with a first-degree relative, and 45.0% reported post-test behavior changes. Awareness was lower among Hispanic (40.8%), Black (49.0%), and Asian American/Pacific Islander (AAPI) (42.2%) populations compared with non-Hispanic Whites (63.4%). Lack of awareness was associated with older age, lower education, limited internet access, and absence of family cancer history, though determinants varied by race/ethnicity. Compared with Whites, AAPI participants were more than three times as likely not to utilize test, while no significant difference was observed for either Hispanic or non-Hispanic African American participants. Factors having a statistically significant effect on utilization included AAPI race/ethnicity group (negative), having a regular provider (positive), and perceptions about progress in curing cancer (positive). Results sharing with healthcare providers and first-degree relatives was positively associated with having a regular provider, White race/ethnicity, higher incomes and having a family cancer history. The influential factors varied across race/ethnicity groups. Conclusion: Substantial racial and ethnic disparities persist in awareness, utilization, and post-test behaviors related to disease-risk genetic testing, with the most notable gaps experienced among AAPI populations. The findings of influential factors vary among racial/ethnic groups. Future research utilizing large, nationally representative datasets and incorporating more granular genetic testing information is warranted to validate and extend these findings. Culturally tailored interventions, stronger provider communication, and inclusive policies are needed to ensure equitable access and reduce disparities in genetic testing and precision medicine.