ICH is the evaluator of the Cambridge Health Alliance (CHA) Vaccine Tripling program, which was focused on increasing the COVID-19 vaccination rate in the communities of Malden, Everett, and Revere. To do this, CHA community health workers (CHWs) reached out to patients vaccinated against COVID-19 and asked them to each reach out to three people they know to ask them to get vaccinated or boosted. The evaluation will take a mixed methods approach, incorporating a quantitative analysis of the community outreach process, and a series of focus groups. The focus groups will be with the community health workers who did the outreach, individuals who received direct outreach from CHWs, and individuals who received outreach from people they knew to get vaccinated. The community focus groups will be conducted in English, Spanish, and Portuguese. The findings will allow CHA to better understand the impact of this innovative approach to increasing vaccination and will inform future healthcare programming using outreach to community members.