The growing diversity of the online health information community is increasingly cited as a limiting factor related to the potential of the Internet as an effective health communication channel and information resource. Public-access Internet portals and decreasing costs of personal computers have created a consensus that unequal access to information, or a "Digital Divide," presents a like problem specific to health care consumers. Access to information, however, is an essential part of the consumer-centric framework outlined in the recently proposed U.S. National Health Information Infrastructure (NHII) and Health Architecture initiatives. To date little research has been done to differentiate the types of health information sought on the Web by different subgroups, linking user characteristics and health-seeking behaviors. Data from a study of consumer Web search activity in a post-intervention era serves as a natural experiment, and can identify whether a "digitally underserved group" persists in the United States. Such an environment would serve to exclude traditionally underserved groups from the benefits of the planned national heath information infrastructure. This exploratory technology assessment study seeks to differentiate and delineate specific behaviors, or lack of desired behaviors, across targeted health care subgroups. Doing so allows the design of more effective strategies to promote the use of the Web as a health education and health promotion tool, under the envisioned shared decision-making, consumer-centric health information model.