Every state medical board operates under a legal definition of the "practice of medicine," and that definition determines when a telehealth encounter falls under its jurisdiction. These definitions were largely written before telehealth was common, so boards have generally interpreted or amended them over time to address remote care, with meaningful differences in how far that interpretation extends.
The core trigger: patient location
In most states, the practice of medicine is considered to occur where the patient is physically located at the time of the encounter, not where the physician is sitting. This means a physician located in one state, treating a patient located in another, is generally considered to be practicing medicine in the patient's state for licensure purposes, even though no travel occurred on either side.
What counts as an encounter
Boards differ on which types of remote interaction actually trigger the practice-of-medicine definition. Real-time video visits are almost universally covered. Asynchronous communication, such as messaging or store-and-forward image review, is treated differently across states, with some boards requiring the same licensure as a live visit and others applying narrower or conditional rules. Simple administrative communication, like scheduling, is typically excluded.
The practice of medicine is generally defined by where the patient sits, not where the physician logs in from.
Established patient exceptions
Some states carve out narrower exceptions for established patients being seen for follow-up care while temporarily out of state, or for physicians providing brief coverage during travel. These exceptions tend to be tightly scoped and are not a substitute for licensure in a state where a physician regularly treats patients.
Why the definition matters operationally
Because the practice-of-medicine definition is what triggers the licensure requirement in the first place, understanding how a specific state's board interprets it is typically the starting point for telehealth compliance planning, before questions of DEA registration, prescribing rules, or compact eligibility even come into play.
Because these definitions and their interpretation vary by state and change over time, always confirm current requirements directly with the relevant state board or agency before making a compliance decision.