Background Trends in acute myocardial infarction (AMI) incidence rates for diverse races/ethnicities are largely unknown, presenting barriers to understanding the role of race/ethnicity in AMI occurrence. Methods and Results We identified AMI hospitalizations for Kaiser Permanente Southern California members, aged ≥35 years, during 2000 to 2014 using discharge diagnostic codes. We excluded hospitalizations with missing race/ethnicity information. We calculated annual incidence rates (age and sex standardized to the 2010 US census population) for AMI, ST‐segment–elevation myocardial infarction, and non–ST‐segment–elevation myocardial infarction by race/ethnicity (Hispanic and non‐Hispanic racial groups: Asian or Pacific Islander, black, and white). Using Poisson regression, we estimated annual percentage change in AMI, non–ST‐segment–elevation myocardial infarction, and ST‐segment–elevation myocardial infarction incidence by race/ethnicity and AMI incidence rate ratios between race/ethnicity pairs, adjusting for age and sex. We included 18 630 776 person‐years of observation and identified 44 142 AMI hospitalizations. During 2000 to 2014, declines in AMI, non–ST‐segment–elevation myocardial infarction, and ST‐segment–elevation myocardial infarction were 48.7%, 34.2%, and 69.8%, respectively. Age‐ and sex‐standardized AMI hospitalization rates/100 000 person‐years declined for Hispanics (from 307 to 162), Asians or Pacific Islanders (from 271 to 158), blacks (from 347 to 199), and whites (from 376 to 189). Annual percentage changes ranged from −2.99% to −4.75%, except for blacks, whose annual percentage change was −5.32% during 2000 to 2009 and −1.03% during 2010 to 2014. Conclusions During 2000 to 2014, AMI, non–ST‐segment–elevation myocardial infarction, and ST‐segment–elevation myocardial infarction hospitalization incidence rates declined substantially for each race/ethnic group. Despite narrowing rates among races/ethnicities, differences persist. Understanding these differences can help identify unmet needs in AMI prevention and management to guide targeted interventions.