tuition reimbursement is contingent on acceptance to a program. I do not believe you can take classes without being enrolled in "A" program. Admissions through School of Continuing Education (aka, GS) is one way to get into a program.
Moreover, Columbia has recently cut back its employee benefits significantly. Starting this fall, no employee can expect to receive more than 3 classes per calendar year. This is in contrast to the previous policy, which allowed an employee to take as many classes as s/he wishes, as long as it does not interfere with one's job responsibilities.
The School of General Studies is entirely separate from the School of Continuing Education.
GS awards bachelor degrees (mostly BAs, some BSs) and a post-baccalaureate certification in premedical sciences. It has rigorous admissions requirements including test scores and transcripts. It is not open enrollment, and you must be working toward a degree (or the postbac premed certificate).
The School of Continuing Education doesn't award undergraduate degrees, and general classes are closer to open enrollment. SCE does have some professional masters degrees, like actuarial science, that I believe do require admissions.
My understanding is that Gac has been at Columbia for 20 years. The first ~7 were taking English classes through the School of Continuing Education. After that he was admitted to GS to pursue a bachelor's degree. However that wasn't automatic for him, or anyone.
