Introduced here are universal modular attachments that can be attached to medication containers. Because a single modular attachment is typically attachable to medication containers of different sizes, the modular attachment can be referred to as a “universal modular attachment.” For example, some universal modular attachments are attachable to any cylindrical eye drop container having a diameter ranging from 20 millimeters (mm) to 27 mm. A connector ring that substantially matches the diameter of the medication container secures the universal modular attachment to the medication container. The connector ring may be fixedly affixed to the medication container, while the universal modular attachment may be detachably connectable to the connector ring. Each universal modular attachment also includes sensor(s) that are configured to detect administrations of medication. For example, the universal modular attachment may include a motion sensor able to detect instances of movement that are indicative of administrations of medication.