OBJECTIVES: To examine prevalence of safe infant sleep practices and variation by sociodemographic, behavioral, and health care characteristics, including provider advice. METHODS: Using 2016 Pregnancy Risk Assessment Monitoring System data from 29 states, we examined maternal report of 4 safe sleep practices indicating how their infant usually slept: (1) back sleep position, (2) separate approved sleep surface, (3) room-sharing without bedsharing, and (4) no soft objects or loose bedding as well as receipt of health care provider advice corresponding to each sleep practice. RESULTS: Most mothers reported usually placing their infants to sleep on their backs (78.0%), followed by room-sharing without bed-sharing (57.1%). Fewer reported avoiding soft bedding (42.4%) and using a separate approved sleep surface (31.8%). Reported receipt of provider advice ranged from 48.8% (room-sharing without bed-sharing) to 92.6% (back sleep position). Differences by sociodemographic, behavioral, and health care characteristics were larger for safe sleep practices (∼10-20 percentage points) than receipt of advice (∼5-10 percentage points). Receipt of provider advice was associated with increased use of safe sleep practices, ranging from 12% for room-sharing without bed-sharing (adjusted prevalence ratio: 1.12; 95% confidence interval: 1.09-1.16) to 28% for back sleep position (adjusted prevalence ratio: 1.28; 95% confidence interval: 1.21-1.35). State-level differences in safe sleep practices spanned 20 to 25 percentage points and did not change substantially after adjustment for available characteristics. CONCLUSIONS: Safe infant sleep practices, especially those other than back sleep position, are suboptimal, with demographic and state-level differences indicating improvement opportunities. Receipt of provider advice is an important modifiable factor to improve infant sleep practices. WHAT'S KNOWN ON THIS SUBJECT: Approximately 3500 infants die annually in the United States from sleep-related sudden unexpected causes. Previous studies have indicated suboptimal adherence to safe infant sleep recommendations and highlighted various sociodemographic disparities and connections with provider advice. WHAT THIS STUDY ADDS: We update previous estimates of safe infant sleep and include a new composite measure assessing the use of separate approved sleep surfaces. We also explore state variation and examine associations between provider advice and each of 4 corresponding sleep-related practices.