Increasing numbers of Americans are living with multiple chronic conditions (MCCs) and disabilities. Addressing health care needs of persons with MCCs or disabilities presents challenges on many levels. For health services researchers, priorities include (1) considering MCCs and disabilities in comparative effectiveness research (CER) and assessing quality of care; and (2) identifying and evaluating the data needed to conduct CER, performance measure development, and other research to inform health policy and public health decisions concerning persons with MCCs or disabilities. Little information is available to guide CER or treatment choices for persons with MCCs or disabilities, however, because they are typically excluded from clinical trials that produce the scientific evidence base. Furthermore, most research funding flows through public and private agencies oriented around single organ systems or diseases. Likely changes in the data landscape—notably wider dissemination of electronic health records (EHRs) and moving toward updated coding nomenclatures—may increase the information available to monitor health care service delivery and quality for persons with MCCs and disabilities. Generating this information will require new methods to extract and code information about MCCs and functional status from EHRs, especially narrative texts, and incorporating coding nomenclatures that capture critical dimensions of functional status and disability.