Best Start—a place-based investment funded by First 5 LA designed to improve the well-being, development and care experienced by children up to age five and their families—has continued to improve and grow in its fourth year and become more firmly established in the downtown Los Angeles pilot community, according to the fourth case study of a longitudinal evaluation of the initiative. Home visiting through Welcome Baby remains the strongest, most tangible and reliable component of the investment. Meanwhile, community capacity building and integration across the components of the investment remain a challenge. Experiences in the pilot community have helped First 5 LA plan for the roll-out of Welcome Baby across 14 new communities.