Due to the high prevalence of polypharmacy in older adults, there is a growing interest among healthcare facilities and practitioners to perform pharmacogenomic testing in this population. However, the complexity of multimorbidity and polypharmacy, the physiologic changes of aging, and the limited direct clinical guidance in this area may cause clinicians to struggle with how to utilize pharmacogenomic test results safely and effectively to guide clinical care. Applying Pharmacogenomics to Optimize Geriatric Care aims to fill this gap by briefly reviewing the foundational science behind each of these complicated factors, how to converge clinical factors with genetic testing, and how to clinically act on pharmacogenomic test panel results. Taken together, this book is a deep dive into applying foundational sciences to establish a framework for approaching complex situations in older adults. It systematically works through case examples of frequently encountered complex patient situations, providing clinicians with practical examples and evidence-based guidance on how to integrate pharmacogenomics with clinical factors to provide personalized patient care in various complex situations. .