Purpose: The primary objective of this study is to validate a transferable methodological standard for qualitative gerontological research through the development of an instrument designed to analyze digital competences as one dimension of broader processes of digital appropriation among older adults within the framework of active aging. Methodology: A focus group script was designed based on Socioemotional Selectivity Theory (SST) and the Selective Optimization with Compensation (SOC) Model. From this, a qualitative codebook was developed and validated through expert judgment and intercoder analysis (Cohen’s Kappa = 0.79). The instrument was administered in 14 focus groups with older adults aged 65 and over, participants in university programs and community social centers. Content analysis was performed using NVivo 14 software. Results: The instrument showed high content validity and a great capacity to systematically categorize perceptions, uses, benefits, difficulties, and training needs related to the use of digital technologies in the older population. The most activated categories included everyday digital practices, technological barriers, learning motivations, and types of social support in digital environments. Conclusions: The developed codebook constitutes a robust and replicable methodological tool for qualitative research on digital inclusion and active aging. Its applicability extends to diverse contexts and profiles of older adults, providing a useful analytical guide for the design of future interventions.