Patient portals have become increasingly prevalent as healthcare providers aim to enhance patient engagement, communication, and satisfaction (1). These online platforms offer patients access to various services, such as scheduling appointments, requesting medication refills, sending messages to healthcare providers, viewing test results, and managing billing information (2). Despite the potential benefits of patient portals, studies have shown that patient engagement can be influenced by a variety of factors, such as demographics, health literacy, and the user experience (3). One factor that may influence patient engagement with portals is the receipt of a bill. Billing has been identified as a key driver of patient dissatisfaction (4), and the potential financial burden associated with healthcare costs can create stress and anxiety for patients (5). However, the impact of receiving a bill on patient portal engagement has not been well studied. Understanding this relationship may help healthcare providers develop strategies to improve patient engagement and satisfaction.