Despite recent guidelines promoting online professionalism, consequences for specific violations by physicians have not been explored. In this article, the authors gauged consensus among state medical boards in the United States (response rate, 71%) about the likelihood of investigations for violations of online professionalism by using 10 hypothetical vignettes. High consensus was defined as more than 75% of respondents indicating that investigation was "likely" or "very likely," moderate consensus as 50% to 75% indicating this, and low consensus as fewer than 50% indicating this. Four online vignettes demonstrated high consensus: Citing misleading information about clinical outcomes (81%; 39/48), using patient images without consent (79%; 38/48), misrepresenting credentials (77%; 37/48), and inappropriately contacting patients (77%; 37/48). Three demonstrated moderate consensus for investigation: depicting alcohol intoxication (73%; 35/48), violating patient confidentiality (65%; 31/48), and using discriminatory speech (60%; 29/48). Three demonstrated low consensus: using derogatory speech toward patients (46%; 22/48), showing alcohol use without intoxication (40%; 19/48), and providing clinical narratives without violation of confidentiality (16%; 7/48). Areas of high consensus suggest "online behaviors" that physicians should never engage in, whereas moderate- and low-consensus areas provide useful contextual information about "gray areas." Increased awareness of these specific behaviors may reduce investigations and improve online professionalism for physicians.