Currently I am using a search term which seems to work since we prefix the sis course id with the term.

string CoursesUrl = @"https://texassouthmostcollege.test.instructure.com/api/v1/accounts/self/courses";

nvc2.Set("search_term", "2018SP");
client2.QueryString = nvc2;
byte[] responseBinary = client2.DownloadData(CoursesUrl);
string response = Encoding.UTF8.GetString(responseBinary);
courses = JsonConvert.DeserializeObject<List<Course>>(response);

Is this currently the only way to limit by term or is there another way I am missing a better way?

Advice is appreciated in this as I have very limited experience with using C# to access REST APIs