Nursing prerequisites typically take one to three semesters to complete, which works out to roughly 4 to 18 months depending on how many courses you take at a time. That range is wide because it hinges on your starting point: someone who already has college credits in biology or psychology has less ground to cover than someone starting from scratch. Part-time students can expect to add one to two years onto that baseline.
What Courses You’ll Need to Complete
The exact list varies by program, but most ADN (associate degree) and BSN (bachelor’s degree) nursing programs pull from the same core pool of subjects: anatomy and physiology (usually a two-course sequence), microbiology, chemistry, introductory psychology, introductory sociology, English composition, statistics, and a communications course. Some BSN programs also require arts and humanities electives, a cultural understanding course, and additional life or physical science credits. At Indiana University, for example, applicants are evaluated on roughly 50 credit hours of prerequisite and general education coursework.
The science courses are the heaviest lift. Anatomy and physiology I and II must be taken in sequence, meaning you can’t start the second course until you pass the first. Microbiology and chemistry can often be taken alongside other courses but may have their own prerequisites (general biology or general chemistry) that add time. If you need to complete those foundational sciences before even reaching the nursing-specific prerequisites, plan for an extra semester.
How Sequencing Affects Your Timeline
Course sequencing is the single biggest factor that stretches your timeline beyond what the raw credit count would suggest. You can’t simply load all your prerequisites into one semester and power through. Anatomy and physiology I must come before anatomy and physiology II. Some programs require general chemistry before organic chemistry or biochemistry. And because these lab sciences are offered on set schedules (often only in fall or spring, not always in summer), a missed enrollment window can delay you by months.
A realistic full-time schedule might look like this: in your first semester, you take anatomy and physiology I, English composition, and introductory psychology. In the second semester, you move to anatomy and physiology II, microbiology, and statistics. If you still need chemistry or additional general education courses, that pushes into a third semester. Students who can take summer courses sometimes shave a full semester off.
The Accelerated Path for Career Changers
If you already hold a bachelor’s degree in a non-nursing field, accelerated BSN programs offer a faster route, but you still need to complete the same science prerequisites. The nursing portion of these programs runs about four semesters of full-time study, including summers. The prerequisite phase depends entirely on how much science your original degree covered. A biology major may need only microbiology and statistics. A business major may need every science course on the list.
Most accelerated programs require a minimum cumulative GPA of 2.7 from your first degree, plus a 3.0 GPA in the required general education courses that will count toward the BSN. You can apply before finishing prerequisites at some schools, but you’ll need to be actively enrolled in the remaining courses and finish them with passing grades before starting nursing classes.
GPA and Grade Requirements
Completing the courses isn’t enough. You need to complete them well. Minimum GPA requirements for nursing program admission typically fall between 2.5 and 3.0 overall, with science courses held to a higher standard. The LA County College of Nursing, for instance, requires a 2.5 overall GPA but a 3.0 in required science courses, with no individual prerequisite grade below a C.
These are minimums. Nursing programs are competitive, and many admitted students carry GPAs well above the floor. If your grades in a prerequisite fall short, retaking the course is an option, but programs limit how many attempts you get. At Indiana State University, a failed prerequisite course can only be repeated once. Failing the same course twice makes you ineligible for admission for at least five years. Failing three different prerequisite courses triggers the same five-year lockout. These policies vary by school, so check your target program’s rules before assuming you can simply retake a course.
Science Credits Can Expire
One timeline factor that catches returning students off guard: science prerequisites have expiration dates at many nursing schools. The most common window is five to seven years from the date of course completion. Lehman College, for example, enforces a seven-year limit on biology and chemistry courses. If your anatomy and physiology credits are older than that when you apply, you’ll need to retake them regardless of the grade you earned.
This policy applies specifically to science courses like anatomy and physiology I and II, microbiology, general chemistry, and organic chemistry. General education courses like English, psychology, and sociology are typically exempt. If you’re returning to school after a career break, check your target program’s expiration policy early. Discovering that your science credits have lapsed after you’ve already spent a semester on other coursework is a painful setback.
In-Person Labs Still Matter
Online prerequisites have become widely available, and some accredited universities now offer anatomy, physiology, microbiology, and chemistry courses entirely online with virtual lab components. However, many nursing programs still require in-person labs for science courses. Indiana University’s accelerated BSN program explicitly requires in-person labs for anatomy, physiology, and microbiology. Before enrolling in an online science course, confirm that your target nursing program will accept it. An accredited online course that isn’t accepted by your specific program is wasted time and money.
Entrance Exams and When to Take Them
Most nursing programs require the TEAS or HESI A2 entrance exam as part of the application. These exams test reading, math, science, and English skills that overlap heavily with your prerequisite coursework. The ideal time to take them is near the end of your prerequisite phase, when the material is freshest. Some programs tie the exam to the application process itself. Chamberlain University, for example, recommends scheduling the HESI within three to five days of applying.
Since many programs allow only a limited number of exam attempts per year, performing well on the first try matters. Finishing your science prerequisites before sitting for the exam gives you the strongest foundation for the science section, which is often the most challenging portion.
Paying for Prerequisites
A common concern is whether financial aid covers prerequisite courses when you haven’t yet been admitted to a nursing program. The answer depends on how your school structures the prerequisite phase. If your college offers a formal pre-nursing studies certificate or associate degree track, those courses typically qualify for federal and state financial aid. Massachusetts, for instance, includes pre-nursing studies as an eligible program for its Community College Nursing Scholarship. If you’re taking prerequisites as a non-degree student at a university without enrolling in a formal program, financial aid options narrow considerably. Enrolling in a declared pre-nursing or general studies program at a community college is often the most affordable and aid-eligible path.
Realistic Timelines by Situation
- Starting from zero, full-time: Two to three semesters (8 to 18 months), depending on how many sequential science courses you need and whether summer classes are available.
- Starting from zero, part-time: Three to five semesters (18 months to 2.5 years), since you’ll likely take only one or two courses at a time.
- Career changer with a bachelor’s degree: One to two semesters (4 to 12 months) if your previous degree covered some general education requirements but not the sciences.
- Returning student with expired science credits: Add one to two semesters for retaking expired courses on top of any remaining prerequisites.
Once prerequisites are done and you’re admitted, the nursing program itself takes roughly two more years for both ADN and BSN tracks, with programs requiring 30 to 40 or more hours per week for classes, labs, and clinical rotations. Planning your prerequisite timeline with that intensity in mind helps you build momentum rather than burning out before the program even starts.