The launch of state certification for community health workers (CHWs) in Massachusetts in 2018 aimed to promote and champion this critical workforce. However, concerns exist about unintentional adverse effects of certification. Given this, we conducted 2 cross-sectional surveys to evaluate this certification policy. We conducted surveys of CHW employers and CHWs in 3 sample frames: community health centers and federally qualified health centers, acute-care hospitals, and community-based organizations. We administered the surveys in 2016 (before certification launch) and 2021 (after certification launch) to answer the following questions: Was certification associated with positive outcomes among CHWs after its launch? Did harmful shifts occur among the CHW workforce and employers after certification launch? Was certification associated with disparities among CHWs after its launch? Certification was associated with higher pay among certified (vs noncertified) CHWs, better perceptions of CHWs among certified (vs noncertified) CHWs, and better integration of certified (vs noncertified) CHWs into care teams. We found no adverse shifts in CHW workforce by sociodemographic variables or in CHW employer characteristics (most notably CHW employer hiring requirements) after certification launch. After certification launch, certified and uncertified CHWs had similar demographic and educational characteristics. However, certified CHWs more often worked in large, clinical organizations while uncertified CHWs most often worked in medium-sized community-based organizations. Our evaluation of Massachusetts CHW certification suggests that CHW certification was not associated with workforce disparities and was associated with positive outcomes. Our study fills a notable gap in the research literature and can guide CHW research agendas, certification efforts in Massachusetts and other states, and program efforts to champion this critical, grassroots workforce.