Definition of 'Pre-Existing Condition'
Any personal illness or health condition that was known and existed prior to the writing and signing of an insurance contract. Health or life insurance policies will often identify a customer's pre-existing conditions before writing an insurance contract for that person, and will typically not cover pre-existing conditions until a specified period of time has elapsed. In some cases, pre-existing conditions may not be covered at all.
Investopedia explains 'Pre-Existing Condition'
Insurance companies typically do not wish to provide insurance coverage for circumstances that are already known to exist.
For example, an insurance company would not be willing to write a fire insurance contract for a homeowner if the company knew that the individual's home had already been destroyed in a fire. In the same way, an insurance company would not be willing to write a life insurance policy for an individual who was already known to be terminally ill.