Objective: Develop and validate a text message bank to support healthier lifestyle behaviors in older adults at risk for cardiovascular disease utilizing a codesign approach. Methods: Initially, the researchers, based on literature, developed a bank of 68 SMS text messages focusing on healthy eating (24 messages), physical activity (24 messages), and motivational feedback (20 messages), based on a scoping review of the literature on promoting behavioral change to engage in healthy lifestyle behaviors. In the next step, a panel of five experts analyzed every subset of SMS text messages. Further validation was conducted by nine older adults (>= 60 years). The user demographics, telephone literacy, understanding, and appeal for every SMS text message were evaluated using a 31-item questionnaire. Results: Participants provided an acceptable understanding of the critical concept found in the 49 SMS text message (physical activity M = 1.73 +/- 0.18; diet M = 1.73 +/- 0.26; motivation M = 1.85 +/- 0.25; range 0-2). The average ratings for physical activity (i.e., likability), healthy eating, and motivation were 8.62 +/- 0.64, 8.57 +/- 0.76, and 8.40 +/- 0.83, respectively (range 0-10). Conclusion: Co-designers were able to identify the technological and content requirements for each text message and infographic to enhance understanding and appeal. Practice implications: A feasibility study will need to be conducted as a next step to testing the effectiveness of text messages in a mobile-based intervention to promote healthy behaviors in older adults at high CVD risk. (C) 2021 Elsevier B.V. All rights reserved.