Importance: COVID-19 has disproportionately killed older adults and racial and ethnic minority individuals, raising questions about the relevance of advance care planning (ACP) in this population. Video decision aids and communication skills training offer scalable delivery models. Objective: To assess whether ACP video decision aids and a clinician communication intervention improved the rate of ACP documentation during an evolving pandemic, with a focus on African American and Hispanic patients. Design, Setting, and Participants: The Advance Care Planning: Communicating With Outpatients for Vital Informed Decisions trial was a pre-post, open-cohort nonrandomized controlled trial that compared ACP documentation across the baseline pre-COVID-19 period (September 15, 2019, to March 14, 2020), the COVID-19 wave 1 period (March 15, 2020, to September 14, 2020), and an intervention period (December 15, 2020, to June 14, 2021) at a New York metropolitan area ambulatory network of 22 clinics. All patients 65 years or older who had at least 1 clinic or telehealth visit during any of the 3 study periods were included. Main Outcomes and Measures: The primary outcome was ACP documentation. Results: A total of 14 107 patients (mean [SD] age, 81.0 [8.4] years; 8856 [62.8%] female; and 2248 [15.9%] African American or Hispanic) interacted with clinicians during the pre-COVID-19 period; 12 806 (mean [SD] age, 81.2 [8.5] years; 8047 [62.8%] female; and 1992 [15.6%] African American or Hispanic), during wave 1; and 15 106 (mean [SD] 80.9 [8.3] years; 9543 [63.2%] female; and 2535 [16.8%] African American or Hispanic), during the intervention period. Clinicians documented ACP in 3587 patients (23.8%) during the intervention period compared with 2525 (17.9%) during the pre-COVID-19 period (rate difference [RD], 5.8%; 95% CI, 0.9%-7.9%; P = .01) and 1598 (12.5%) during wave 1 (RD, 11.3%; 95% CI, 6.3%-12.1%; P < .001). Advance care planning was documented in 447 African American patients (30.0%) during the intervention period compared with 233 (18.1%) during the pre-COVID-19 period (RD, 11.9%; 95% CI, 4.1%-15.9%; P < .001) and 130 (11.0%) during wave 1 (RD, 19.1%; 95% CI, 11.7%-21.2%; P < .001). Advance care planning was documented for 222 Hispanic patients (21.2%) during the intervention period compared with 127 (13.2%) during the pre-COVID-19 period (RD, 8.0%; 95% CI, 2.1%-10.9%; P = .004) and 82 (10.2%) during wave 1 (RD, 11.1%; 95% CI, 5.5%-14.5%; P < .001). Conclusions and Relevance: This intervention, implemented during the evolving COVID-19 pandemic, was associated with higher rates of ACP documentation, especially for African American and Hispanic patients. Trial Registration: ClinicalTrials.gov Identifier: NCT04660422.