Adults with cognitive impairment are considered a vulnerable population. The conditions associated with cognitive impairment, such as dementia and delirium, cause great suffering to affected patients and their families. Improving clinical care for these conditions depends on research involving cognitively impaired participants. Cognitive impairment is at times associated with partial or full impairment of the capacity to consent to research. This both limits the ability of the individual to consent personally to research participation, and also increases pressure upon Institutional Review Boards (IRBs) and investigators to place additional safeguards for the appropriate participation of cognitively impaired individuals in research. While the ethical and legal principles permitting and safeguarding the participation of cognitively impaired persons in research are generally agreed upon, there are no specific methods that operationalize these principles in a language that can be used by IRBs and researchers to guide their day-to-day work in this area. This document contains recommendations that IRBs and investigators can use to operationalize the informed consent process for individuals with cognitive impairment. In situations in which IRBs might not have specific policies in this area, this guideline may also serve as the foundation for such policies. The recommendations discuss when to consider that cognitively impaired participants might be involved in a research project, the use of screening for cognitive impairment, the conduct of assessments evaluating capacity to consent to research, situations in which proxies might consent for research participation in the place of cognitively impaired participants, how to go about identifying appropriate proxies, and how to deal with the loss of consent capacity in the course of a research project.