Positive health outcomes hinge on the effective use of medications especially among vulnerable, chronically ill, and aging populations. Yet, increasingly powerful and complex drug combinations are used to treat patients with chronic diseases and multiple health conditions. As treatment complexity increases the potential grows for non-adherence to medications due to side-effects, drug-disease interactions, costs, and patient confusion about medicines. Pharmacists are the medication experts on a health care team. Working in collaboration with the patient and the prescriber, pharmacists offer solutions that foster medication adherence, improve clinical outcomes and decrease drug-related adverse events. Their accessibility, extensive knowledge of drug therapy, and trustworthiness in the minds of consumers open many opportunities for pharmacists to expand their reach in preventing drug-related problems in patients with chronic diseases.