The Ventanillas de Salud (VDS - Health Windows) are a culturally sensitive outreach program within the 49 Mexican Consulates in the United States that provides information and health care navigation support to underserved and uninsured Mexican immigrants. During the COVID-19 pandemic the VDS rapidly transitioned to remote operations adding new services. Based on the EquIR implementation framework, this qualitative study investigates how adaptations to improve emergency preparedness were performed. We conducted motivational interviews with three actors - six VDS coordinators, eight partner organizations, and ten VDS users- in two VDS, Los Angeles and New York, to document specific needs of the target population and identify implementation processes to adapt and continue operating. The VDS adapted their model by adding new services for emerging needs, by switching service provision modalities, and by expanding the network of partner organizations. According to the VDS staff, these adaptations increased their topics, depth, reach, and diversified their users. Users had mostly positive opinions about the VDS adaptation, although they highlighted some heterogeneity across service provision. The VDS is a public health intervention able to serve a marginalized population and its implementation offers valuable lessons to complement health systems and to improve preparedness and resiliency for future crises.