Dual enrollment (DE)--taking college courses in high school--can help improve student access to and success in college. In the past few years, California has passed legislation that expanded DE through the College and Careers Access Program (CCAP) and enacted reforms in assessment and placement for English and English as a Second Language (ESL). Both are intended to boost access and accelerate academic progress among historically underserved populations such as Latino, Black, and first-generation students. The state has also recently invested nearly $700 million for K--12 and community college districts to expand and support DE. Moreover, agreements and initiatives across California's public higher education system increasingly promote more access to DE, including the completion of at least 12 college credits during high school. This policy brief presents how effective these expansion efforts been so far, and changes that are seen in student participation and outcomes.