'upon enrolling' is correct and usable in written English.
It means "when you begin school or a course of study". For example, you could say: "Upon enrolling in college, I was required to take many classes outside of my major."
But senior citizens often encounter difficulties upon enrolling in private Medicare plans.
They do a lot of other things, as Joan and Barri learn upon enrolling at the fictional University of the Midwest.
Men set dogs upon enrolling officers who came to the house, and women sometimes tossed pots of hot water on them.
Actually, it wasn't even business he had on his mind upon enrolling in college.
Welfare participation would also increase as more individuals leave the labor force and become aware of other welfare programs upon enrolling in Medicaid.
At 11 years old, upon enrolling in secondary school, I faked an older birthdate and joined Myspace.
Among 1155 participants in the study, 290 were confirmed to be HIV positive (25.1 %), including 48 men newly diagnosed upon enrolled in the current study and 242 previously diagnosed.
While kindergarten farm B near a city had no difficulty attracting its 14 clients, farm B in a rural area has a smaller population of children to draw upon, and enrolled only half the number of clients.
He began his education at the West Nottingham Academy, and upon graduating enrolled at St . Johns College in Annapolis, Maryland.
All midwives were invited to complete an online pre-questionnaire upon being enrolled as a participant in the study.
Upon acceptance, students participate by enrolling in HD4260 (Translational Research in Memory and Neuroscience) or HD4010 (Empirical Research), and receive training that will prepare them to conduct independent research on these topics as part of laboratory research teams and for honors and graduate theses.
