Background Team-based models of cardio-obstetrics care have been developed to address the increasing rate of maternal mortality from cardiovascular diseases. Cardiovascular clinician and trainee knowledge and comfort with this topic, and the extent of implementation of an interdisciplinary approach to cardio-obstetrics, are unknown. Methods and Results We aimed to assess the current state of cardio-obstetrics knowledge, practices, and services provided by US cardiovascular clinicians and trainees. A survey developed in conjunction with the American College of Cardiology was circulated to a representative sample of cardiologists (N=311), cardiovascular team members (N=51), and fellows in training (N=139) from June 18, 2020, to July 29, 2020. Knowledge and attitudes about the provision of cardiovascular care to pregnant patients and the prevalence and composition of cardio-obstetrics teams were assessed. The widest knowledge gaps on the care of pregnant compared with nonpregnant patients were reported for medication safety (42%), acute coronary syndromes (39%), aortopathies (40%), and valvular heart disease (30%). Most respondents (76%) lack access to a dedicated cardio-obstetrics team, and only 29% of practicing cardiologists received cardio-obstetrics didactics during training. One third of fellows in training reported seeing pregnant women 0 to 1 time per year, and 12% of fellows in training report formal training in cardio-obstetrics. Conclusions Formalized training in cardio-obstetrics is uncommon, and limited access to multidisciplinary cardio-obstetrics teams and large knowledge gaps exist among cardiovascular clinicians. Augmentation of cardio-obstetrics education across career stages is needed to reduce these deficits. These survey results are an initial step toward developing a standard expectation for clinicians' training in cardio-obstetrics.