continuing education 
noun [mass noun]
Education provided for adults after they have left the formal education system, consisting typically of short or part-time courses: [as modifier]: continuing education courses a continuing education programme...
- One way to extend your professional shelf life is continuing education with short courses taught by experts in the field.
- I recommend they go to a community college or continuing education course to learn how to run a business.
- There are continuing education courses, personal trainers, committees, and councils to fuss over.