ImportanceAfter publication of US Preventive Task Force Prostate-Specific Antigen (PSA) screening guidelines in 2008 and 2012, there have been documented associations with incidence and stage distributions of prostate cancer. It is unclear if these changes were temporary or differed by age or race and ethnicity.ObjectiveTo assess the association of 2008 and 2012 PSA guidelines with prostate cancer incidence by age and race and ethnicity in the US.Design, Setting, and ParticipantsThis cross-sectional study evaluated prostate cancer incidence from 2005 to 2018 in the US using data from the US Cancer Statistics public use database. Data were analyzed from August 2020 through June 2022.Main Outcomes and MeasuresThe primary outcome was the year when rates of prostate cancer incidence changed directionality by age and race and ethnicity. Age-adjusted incidence rates of prostate cancer and corresponding 95% CIs were created, followed by join point regression analysis to evaluate trends of age-adjusted incidence rates of prostate cancer by age, race, Hispanic ethnicity, and stage of diagnosis.ResultsAmong 2 944 387 men with prostate cancer, 2 869 943 (97.5%) men were aged 50 years and older. Men aged 50 years and older accounted for 185 476 of 191 533 Hispanic individuals (96.8%) and 2 684 467 of 2 752 854 non-Hispanic individuals (97.5%). Men aged 50 years and older accounted for 427 016 of 447 847 African American individuals (95.4%), 12 141 of 12 470 American Indian or Alaska Native individuals (97.4%), 61 126 of 62 159 Asian or Pacific Islander individuals (98.3%), and 2 294 171 of 2 344 392 White individuals (97.9%). Men with unknown race (77 519 men) were excluded from the analysis. A decrease in age-adjusted rate of prostate cancer after the 2008 guideline change was observed in all age groups by race and ethnicity. For example, among African American men ages 65 to 74 years, 10 784 of 807 080 men (1.34%) had a prostate cancer diagnosis in 2007 vs 10 714 of 835 548 men in 2008 (1.28%). The mean annual age-adjusted incidence rates of prostate cancer per 100 000 men were 157.7 men (95% CI, 157.4-158.0 men) in 2005 to 2008 and 131.9 men (95% CI, 131.6-132.2 men) in 2009 to 2012. The number of inflections and annual percent changes (APCs) for segments separated by inflections varied by age, race, and Hispanic ethnicity. For men ages 65 to 74 years, the APC was −6.53 (95% CI, −9.28 to −3.69) for 2009 to 2014 among African American men (2 join points), −5.96 (95% CI, −6.84 to −5.07) for 2007 to 2018 among American Indian or Alaska Native men (1 join point), −6.52 (95% CI, −9.22 to −3.74) for 2007 to 2014 among Asian or Pacific Islander men (2 join points), −7.92 (95% CI, −11.36 to −4.35) for 2009 to 2014 among Hispanic men (2 join points), and −7.02 (95% CI, −9.41 to −4.57) for 2007 to 2014 among White men (2 join points).Conclusions and RelevanceIn this study, men in different age, race, and ethnicity groups had different APC patterns after 2008 and 2012 PSA screening guideline changes. These findings may provide important data on the timing and durations of changes in cancer diagnoses that are associated with changes in PSA screening recommendations and may be valuable for targeted strategies to reduce regional- and distant-staged cancers.