Keep in mind the minimum requirements for remaining in good academic standing, and contact an advisor if you have concerns about your academic performance.
To remain in good academic standing, you must:
Some students have additional requirements and restrictions that are not related to academic standing: for example, international students, NCAA athletes, and students on outside fellowships usually cannot go below 12 units in a quarter. If you think you might earn fewer than 12 units, be sure to consult a UAR advisor to discuss your individual case.
Be aware of the difference between enrolling in units and earning units. All students need to enroll in at least 12 units at the beginning of every quarter. At the end of the quarter, when your transcript shows a passing grade for each course, then you have earned the units. You can earn units with any grade of D-minus or above, or with a CR (Credit) grade. NP (No Pass) and NC (No Credit) are failing grades that do not earn units. Be especially careful to consult a UAR advisor about incompletes or repeating classes. Incompletes do not count as earned units until the final grade has been entered in Axess. Repeating classes can result in losing previously earned units and bring you under the 36 units every three quarters rule.
Depending on your individual situation, there may be different rules about enrolling and earning units, so be sure to consult advisors. You can read more about academic standing in the Stanford Bulletin.
Financial Aid also has separate rules for Satisfactory Academic Progress that students on financial aid should understand.