Is costochondritis considered a disability?

No: Disability means a person cannot do something that a person (without a particular illness or problem) can do. Costochondritis is not a disability because a person with costochondritis can still do many or most of the things that people without costochondritis can do. However, one can be disabled in one's own profession... which means that costochondritis may be a disability for a trumpet player.

Disability: Disability means that there is some medical condition that prevents you from being able to carry out your activities of daily life- so if the costochondritis is affecting your work, or life then it may be creating a disability for you.