A four-year plan looks perfect until you realize CMSC 401 sits in junior year while CMSC 330 is still scheduled for senior spring. Testudo will block you at registration; your advisor will ask for a rewrite. Orbit catches those mistakes while you are still dragging courses on the plan board. Place a class before its prerequisite is satisfied and you get an immediate warning, plus one-click fixes to add the missing course or jump to the right term.
Why prerequisite mistakes are expensive
Wrong-term ordering is silent until it is not. You lose a seat in a gateway course, push graduation back a semester, or stack two lab-heavy classes because a prereq chain shifted. Mapping prerequisites on paper works for one major requirement; it falls apart when you add a minor, transfer credits, and gen-ed wildcards across eight semesters.
What Orbit checks on your plan
- Missing prerequisites: a course on the plan whose prereqs are not completed or scheduled earlier
- Wrong-term ordering: a dependent course placed before its prerequisite in the timeline
- Permission requirements: flagged separately, with an option to record a waiver when your department approved access
Checks use your transcript import, prior credits, AP exams, and math or language placements so completed work is not double-counted as missing.
How to read warnings and fix them
Open Four-Year Plan and watch the insights bar. When prerequisite issues exist, a pill shows the count. Individual courses with blocking problems get a warning icon on the term card. Click through to the conflict dialog: it explains what is wrong and offers to add the missing prerequisite to an earlier term, scroll to the affected course, or jump to the term where the prereq belongs.
- Import your transcript so completed courses are excluded from false warnings.
- Drag a course between terms. Orbit validates the move before it sticks.
- If a warning appears, open the issue from the insights bar or the course icon.
- Use Add prerequisite or Jump to term, then re-check until the insights bar clears.
Pro tip: import credits first
Prerequisite tracing is only as good as the history Orbit knows about. Upload your unofficial transcript before you build or suggest a plan. That keeps CMSC 250 marked complete so CMSC 330 does not look blocked. See Upload Your UMD Transcript Once. Orbit Fills In the Rest..