Emergent literacy (EL) interventions are effective at fostering foundational skills for reading and writing. During the COVID-19 pandemic schools faced several challenges to maintain these interventions, namely changing face-to-face to remote modalities. In this study, the effects of a multi-tier emergent literacy intervention are examined, delivered both in face-to-face and remote modalities, during the second COVID-19 pandemic lockdown. The intervention was delivered to 102 preschool Portuguese children (aged 5-6 years) according to the Multi-Tier Systems of Support (MTSS) framework and evaluated using a pre and post-test design and a single group. The results showed significant gains after the intervention in all emergent literacy skills evaluated: phonological awareness, vocabulary, print concepts, alphabet knowledge, and emergent writing. These findings highlight the relevance of systematic interventions that implement universal screenings, progress monitoring and decision-making processes based on children's performance, and the potentialities of using mixed modalities (face-to-face and remote) to deliver such interventions in uncertain times.