Temporary medical insurance (and sometimes called short term medical insurance) provides health insurance for a period of (generally) 30 days to a year (some companies may not constrict the coverage period) for people under 65 and for their dependents who are between permanent medical plans.
These health plans are nonrenewable yet you may purchase an additional policy beyond the initial period if you are insurable, and any condition that occurred during your prior coverage that can be considered a preexisting condition under the subsequent coverage period.