To be too old to remain in an age-based classification or receive age-based services. When you turn 26, you will age out of your parents' health insurance coverage.When these kids turn 10, they'll age out of the after-school program.
[for an adult] to grow [mentally or in years] out of certain behavior or out of a group or classification that is based on age. (Jargon.) Most of them tend to age out at about 35.
To reach an age at which one is no longer eligible for certain special services, such as education or protection, from an authority: Unfortunately I have aged out of the special student scholarship program, so I have to pay full price for these classes.