Systematic reviews offer clarity about the effectiveness of interventions based on the best available evidence. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 statement updated previous guidance to ensure transparency in the reporting of systematic reviews of intervention effectiveness. To adhere to the 27 items of PRISMA 2020, aging-focused researchers must specify the choice of age-based criteria for the review, comprehensively identify studies, select the most important outcomes that will therefore be collected, define the effect measures (e.g., odds ratio), describe investigations of the causes of heterogeneity (e.g., different settings), assess and report the risk of bias including blinding of participants and missing outcome data for results that contribute to each meta-analysis, and discuss the implications of the findings for practice, which will often include some uncertainty. This article provides guidance on overcoming the specific challenges faced by aging-focused researchers in transparently reporting a systematic review.