The Consumer Assessment of Healthcare Providers and Systems (CAHPS®) surveys ask consumers and patients to report on their experiences with health care services. CAHPS is a public-private program, led by the Agency for Healthcare Research and Quality (AHRQ). CAHPS surveys go beyond producing patient satisfaction ratings by asking patients to report on their experiences with health care services. Reports about care are regarded as more specific, actionable, understandable, and objective than general ratings alone. From the original survey of health plans,1 CAHPS has evolved into a family of surveys, focusing on different settings and populations. One of the purposes of the CAHPS surveys is to report quality information for accountability and consumer decision-making. In addition to developing the survey instruments, the CAHPS program has provided instructions for analyzing the data and constructing composite measures, as well as formats for reporting the data. Another important purpose of CAHPS is to serve as a tool for quality improvement. This special issue focuses on 2 supplements to the Clinician/Group CAHPS—the CAHPS Cultural Competence Item Set and the CAHPS Item Set for Addressing Health Literacy—and 1 supplement to the CAHPS Hospital Survey—the Hospital CAHPS Item Set for Addressing Health Literacy. These item sets embody the growing commitment of the CAHPS program to produce surveys that can be used for quality improvement and reporting purposes. The development of the CAHPS Cultural Competence Item Set constitutes a major advance in the promotion of culturally and linguistically appropriate services. Although the National Standards for Culturally and Linguistically Appropriate Services in Health Care called for organizations to conduct ongoing assessments and develop metrics for accountability,2 there have been no validated instruments to measure how culturally competent an organization is from the patient’s perspective. The AHRQ, the Commonwealth Fund, and the CAHPS grantees collaborated to fill this void. The CAHPS Cultural Competence Item Set asks patients to report on their experiences with issues such as language access, trust, complementary and alternative medicine, patient-provider communication, and discrimination. Critical for identifying disparities is examining measurement equivalence across race, ethnicity, and language. The articles in this journal supplement not only document the reliability and validity of these scales across race/ethnicity and language (English and Spanish), but also link some of these measures to health outcomes. Development of the CAHPS Item Set for Addressing Health Literacy also represents a watershed moment. As articulated in the Affordable Care Act of 2010, health literacy is the capacity to obtain, communicate, process, and understand basic health information and services to make appropriate health decisions. There is increased awareness that individuals’ inability to understand and use health information and services is partly a function of the complexity of the information and system.3 There is also a growing recognition that health care professionals and organizations have a responsibility to improve patients’ understanding of health information.4,5 There, however, have been no validated measures of whether providers are following recommendations for health literacy practices, and little guidance to help them know if well-intentioned efforts are effective.6,7 The CAHPS Item Set for Addressing Health Literacy item set breaks new ground by measuring, from the patients’ perspective, to what extent health care professionals have succeeded in reducing health literacy demands. The CAHPS Item Set for Addressing Health Literacy includes questions about interpersonal communication between providers and patients, focusing on specific behaviors that promote or detract from understanding. It also queries about critical prevention and treatment topics, such as self-management of health conditions and medicine instructions. Finally, it assesses the health literacy environment outside the clinical encounter by asking about forms patients are asked to sign and to complete, including whether help was offered. The need for health literacy performance measures, and identification of improvement opportunities, is not limited to the ambulatory care setting. The importance of addressing health literacy in hospitals has gained traction as hospitals have realized that clear communication is an important component of reducing preventable readmissions.8 AHRQ and CAHPS grantees, in consultation with the Centers for Medicare and Medicaid Services, developed the Hospital CAHPS Item Set for Addressing Health Literacy. The item set measures the same domains as the Clinician/Group supplement, and also includes questions about discharge instructions and language assistance for speakers of languages other than English. These CAHPS supplemental item sets would not have been possible without the guidance and contributions of Charles (Chuck) Darby, an AHRQ project officer and founding father of CAHPS. Chuck’s untimely death in March 2009 was a huge loss to the field of patient-centered care, and to his colleagues within and beyond AHRQ. Chuck, with his AHRQ colleague Christine Crofton, shepherded CAHPS from a novel idea into a national program with multiple surveys and thousands of users. Due in large part to Chuck’s professional and personal commitment, there is national recognition that patient and families’ experiences with the health care system must be considered when measuring and reporting on the quality of care. Chuck dedicated 12 years of his life to ensuring that we have scientifically rigorous tools to assess health care from the patient’s perspective, thereby helping to chart a path to improving health care quality for all. We, in turn dedicate this Medical Care supplement to Chuck Darby.