Systems and methods are provided for determining whether and/or when a patient is taking his or her medication and, when appropriate, providing reminders and/or alerts to the patient to improve adherence to a medication regimen. In some embodiments, a medication container is provided that includes a capacitance sensor for sensing the contents of the medication container (e.g., pill count or quantity of liquid medication). The capacitance sensor may include interleaved or interdigitated electrodes oriented vertically, horizontally, or angularly (e.g., diagonally) relative to an axis of the medication container. Reminders and/or alerts to the patient may be triggered based at least in part on the contents of the medication container, when a cap of the container was last opened and/or closed, the location of the medication container, and/or the container's surroundings.