PA School Prerequisite Refresh: How to Handle Expired Science Courses- A practical guide for PA school applicants whose science prerequisites are aging out — covering program-by-program recency rules, which courses to refresh first, and how to compress a year of refresher coursework into a single semester.
If you completed your science prerequisites more than five years ago — perhaps as part of an undergraduate biology, exercise science, or psychology degree — you may be discovering an unwelcome surprise as you prepare your CASPA application: many PA programs will not accept those courses anymore. They have expired under program recency rules, and you need to take them again.
This is one of the most common scenarios in pre-PA preparation, and it catches more applicants off guard than almost anything else. A 32-year-old career changer with a strong undergraduate biology degree from age 22 may have assumed that her prerequisites were locked in for life. They were not. The Physician Assistant Education Association (PAEA) reports that roughly half of CASPA-participating programs apply a recency requirement to science prerequisites — typically five, seven, or ten years.
The good news is that prerequisite refresh is one of the most clean-cut projects in pre-PA preparation. Unlike GPA repair (where the math is complicated by retake rules) or PCE accumulation (where you need hundreds of hours), refresh work is mechanical: identify which courses are expired at your target programs, retake those courses at an accredited institution, and submit fresh transcripts. With self-paced online prerequisite coursework, the entire refresh stack — typically four to six courses — can be completed in six to ten months without quitting your current job.
This guide walks through everything you need to know: which programs apply recency rules and how strict they are, how to identify which of your courses are expired, the right order to refresh courses in, what counts as a “refresh” versus a full retake, and how to compress what would be 18 to 24 months of traditional academic coursework into a single working year.
| In this guideHow PA program recency rules actually workThe 5/7/10 year breakdown across CASPA programsWhich prerequisites “expire” and which don’tHow to audit your transcript for expired coursesThe right order to refresh courses inRefresh vs. full retake: what countsA realistic 6-to-10 month refresh planCost of a full prerequisite refreshHow PrereqCourses.com handles refreshers |
PA program recency rules exist because admissions committees believe — with reasonable evidence — that biology and chemistry move forward fast enough that a course taken twelve or fifteen years ago no longer reflects the material as it is understood and taught today. The molecular biology and immunology taught in 2009 was substantially different from the molecular biology and immunology taught in 2024. The same is true, to varying degrees, of microbiology, biochemistry, and anatomy & physiology.
The practical effect for applicants is that science prerequisites carry an expiration date. Most programs publish their recency policies on their prerequisite pages. The wording varies, but the structure is similar: science coursework must be completed within the past X years to be acceptable as a prerequisite. Anything older must be retaken.
PA program recency policies fall into four broad patterns, with different implications for applicants:
| Policy Type | How Common | What It Means for You |
|---|---|---|
| No recency rule | ~45% of programs | Prerequisites from any era are acceptable. If all your target programs fall here, you may not need to refresh anything. |
| 10-year recency | ~20% of programs | Science courses must be completed within the past 10 years. Most applicants under 35 with undergraduate science degrees are unaffected. |
| 7-year recency | ~20% of programs | Science courses must be completed within the past 7 years. Captures most career changers and reapplicants whose degrees are more than a few years old. |
| 5-year recency (strictest) | ~15% of programs | Science courses must be completed within the past 5 years. The most aggressive policy; affects even recent college graduates if they spent 2–3 years working before applying. |
Programs measure recency from the course completion date to either: (a) the date you submit your CASPA application, or (b) the program’s matriculation date. The difference matters in some cases. If a program measures recency to the matriculation date, a 7-year-old prerequisite taken in August 2018 is acceptable for a fall 2025 matriculation but not for a fall 2026 matriculation.
When in doubt, measure to the matriculation date — that is the stricter standard, and being safe under the stricter standard means you are safe under both.
| Reality check: how strict are programs actually? In practice, programs vary in how strictly they enforce published recency rules. Some programs will accept a course that is one or two months past the official cutoff if everything else in the application is strong; others apply the rule literally and reject applicants whose A&P I expired in March when the application deadline was June. Plan around the published rule, not the informal practice. Programs cannot reward you for assuming flexibility, but they can reject you for relying on it. |
Not every prerequisite is subject to recency rules. The pattern is consistent across PA programs: science prerequisites expire, and almost everything else does not. Understanding the distinction lets you focus refresh work on the courses that actually need it.
These are the science courses programs treat as expiring under recency rules:
These are usually exempt from recency rules even at programs with strict science policies:
This is actually good news for most refresh-stage applicants. The expensive, lab-heavy, time-consuming prerequisites are the ones that expire — but the cheap, lecture-only prerequisites typically do not. A career changer with a 15-year-old biology degree may need to refresh A&P, Micro, Bio, and Chemistry, but probably does not need to retake Statistics, Psychology, or English Composition.
| Lab is the leading indicator. A simple heuristic: if the course had a lab component, it probably expires. If it did not, it probably does not. Lab sciences are the courses programs treat as evolving most rapidly. Lecture-only social science and quantitative prerequisites are treated as durable. |
Before you enroll in a single refresh course, do the audit. Refreshing prerequisites you do not actually need is a common and expensive mistake; failing to refresh prerequisites you do need is a worse and costlier one. The audit takes a few hours and saves both kinds of mistakes.
Recency rules vary by program, so the question of which of your prerequisites are expired depends entirely on where you plan to apply. Build your target list before auditing your transcript — typically 10 to 15 PA programs you are seriously considering.
This is also the right time to think about diversity of policies. A target list weighted toward programs with no recency rule, or with 10-year recency rules, leaves you more flexibility. A target list weighted toward 5-year-recency programs forces a more aggressive refresh.
For each program on your list, find the prerequisite page on the admissions website and locate the recency policy. The exact language varies, but you are looking for sentences like:
If a program’s prerequisite page does not mention recency at all, default to “no recency rule applies” — programs that enforce recency rules almost always publish them explicitly because they receive too many questions otherwise. But verify with an email if you are unsure.
In a simple spreadsheet, list each of your prior science prerequisites in rows and your target programs in columns. For each cell, mark whether the course is acceptable at that program based on its recency policy. The pattern that emerges tells you exactly what you need to refresh.
A simplified version might look like this:
| Your Course (completion year) | Program A (10-yr) | Program B (7-yr) | Program C (5-yr) | Program D (none) |
|---|---|---|---|---|
| A&P I (2014) | Yes | No | No | Yes |
| A&P II (2014) | Yes | No | No | Yes |
| Microbiology (2014) | Yes | No | No | Yes |
| Gen Chem I (2013) | Yes | No | No | Yes |
| Statistics (2013) | Yes | Yes | Yes | Yes |
In the example above, Statistics is acceptable everywhere and does not need to be refreshed. A&P I, A&P II, Microbiology, and General Chemistry I are expired at the 7-year and 5-year programs but acceptable at the 10-year and no-recency programs. If your application strategy depends on competing at the stricter programs, you need to refresh those four courses. If you are content to apply only to the more permissive programs, you may not need to refresh at all.
Once you can see the pattern, three strategic responses are typical:
If you have multiple courses to refresh, sequence matters. Some courses build on others, some are more time-critical because they are more heavily weighted in admissions screening, and some are easier to fit into a busy schedule. The optimal refresh sequence for most applicants:
Why first: These are the most heavily weighted PA prerequisites at virtually every program. An expired A&P sequence is the biggest single hole in a refresh-stage application. They are also the longest courses (4 credits each with lab), so finishing them early in your refresh window protects against schedule slippage.
A&P I should generally be completed before A&P II, though some programs accept them in either order. Plan for two to three months of focused work on A&P I, followed by two to three months on A&P II. With self-paced enrollment, the two together can be completed in four to five months.
Why next: Microbiology is heavily weighted, but shorter than A&P and conceptually distinct, so it can be taken in parallel with A&P II if your schedule allows. General Chemistry I and II are foundational but slightly less heavily weighted than A&P or Micro in screening, so they fit naturally in the middle of the refresh sequence.
General Chemistry II should follow General Chemistry I. Microbiology can be slotted in at any point after you have refreshed at least one semester of biology background.
Why last: Foundational sciences (Gen Bio I & II) are often less strictly enforced under recency rules than upper-level sciences (A&P, Micro, Biochem). Some applicants find that their target programs accept old Gen Bio coursework even when they require recent A&P and Micro. Verify program-by-program before refreshing Bio.
Organic Chemistry and Biochemistry are typically refreshed only if they are required by your target programs AND are expired under the applicable recency rule. Not every program requires Orgo or Biochem, so check carefully before adding either to a refresh plan.
| Don’t refresh in alphabetical or transcript order. It’s surprisingly common for refresh-stage applicants to start with whatever the first expired course is on their old transcript — say, Biology I because it comes alphabetically first. That is a mistake. Refresh in weight-and-time order: A&P I and II first because they matter most, then Microbiology, then Chemistry, then Biology and the others. The goal is to finish the most important courses early in case your timeline gets compressed. |
A frequently asked question among refresh-stage applicants: do I need to take a full course again, or is some shorter form of refresh acceptable? The answer at every CASPA-participating PA program is the same — and it is more straightforward than most applicants assume.
A refresh is a full, transcripted course retake. PA programs do not accept any shorter form as satisfying their prerequisite requirements. There is no PA-school equivalent of a continuing-medical-education credit, a brush-up certificate, or a non-credit MOOC that counts toward the prerequisite recency requirement. Every refreshed prerequisite must be a full college course, transcripted by a regionally accredited US institution, with a letter grade and the same credit hours the program would require for any other applicant.
This sounds restrictive but it is actually clarifying. You do not need to wonder whether some intermediate option might count. The only option that counts is a full transcripted retake — and that retake is what this guide is built around.
The refresh-stage applicant has a structural advantage over the typical pre-PA applicant: you already have most of the prerequisites done, you already have a bachelor’s degree, you already have PCE in many cases (refresh-stage applicants are often working in healthcare-adjacent roles), and you have a clear, finite project in front of you. The only question is how to compress the refresh work into the time you have before the next CASPA cycle.
Typical profile: A career changer or reapplicant whose A&P is expired but whose chemistry and other sciences are still within recency rules at most target programs.
Total refresh window: 4–6 months from start to last transcript sent to CASPA. Comfortable timeline; fits inside any CASPA cycle.
Typical profile: A career changer with a biology, exercise science, or psychology degree from 8–12 years ago whose full science prerequisite stack has expired under 5-year and 7-year recency rules.
Total refresh window: 7–8 months. Tight but workable for someone with weekend and evening hours to commit. Many applicants pair Months 1–2 with continued full-time work, then reduce hours during the heavier middle months.
Typical profile: Older career changers (40+) with science degrees from 15–25 years ago, where every science prerequisite has expired at every program with any recency rule.
Total refresh window: 9–10 months. Aggressive but achievable, especially for applicants who are not balancing the refresh against a demanding full-time job or are willing to reduce work hours during the refresh window.
| Why self-paced is decisive for refresh-stage applicants. The standard semester-based academic calendar makes any of the scenarios above difficult. A traditional university would require 18 to 24 months of semester-based scheduling — start in fall, finish in spring, repeat — to complete the same work that self-paced online prerequisite coursework completes in 6 to 10 months. The reason is structural: traditional courses run 15–16 weeks regardless of how fast you can master the material, with summer and winter gaps you cannot skip. Self-paced courses let you finish in 6–10 weeks when you are ready, then immediately start the next course. |
Refresh costs vary widely depending on where you complete the courses. Because refresh-stage applicants are not building cumulative credit toward a degree, the per-credit cost analysis is unusually pure: you are paying for transcripted credit and the lab kit, nothing else.
| Provider Type | Per 4-Cr Course | 4-Course Refresh | 6-Course Refresh |
|---|---|---|---|
| In-state community college | $600–$900 | $2,400–$3,600 | $3,600–$5,400 |
| Out-of-state community college | $1,200–$2,000 | $4,800–$8,000 | $7,200–$12,000 |
| Public four-year university (in-state) | $1,600–$3,000 | $6,400–$12,000 | $9,600–$18,000 |
| Post-baccalaureate program | $3,200–$6,000 | $12,800–$24,000 | $19,200–$36,000 |
| PrereqCourses.com (self-paced) | $675–$695 | $2,700–$2,780 | $4,050–$4,170 |
For a typical four-course refresh, the cost difference between PrereqCourses.com and a post-baccalaureate program is roughly $10,000–$20,000. Even compared to a public four-year university, the savings are typically $4,000–$9,000. Community college is competitive on dollars per course, but loses on time-to-completion: the 4–5 month PrereqCourses refresh becomes a 12–18 month community-college refresh because of semester scheduling.
For deeper analysis, see the complete cost breakdown of PA school prerequisites and our community college vs. online comparison.
Refresh work is fundamentally about compression. You already have a bachelor’s degree, you do not need a second one, and you do not need a credit-by-credit slow build over multiple years. You need to take a defined set of prerequisite courses, earn strong grades, get the transcripts to CASPA, and move on with your application. Every structural decision at PrereqCourses.com is built around that exact need.
All PrereqCourses coursework is delivered through Upper Iowa University, a Higher Learning Commission–accredited regional university that has been awarding degrees since 1857. Coursework appears on an official UIU transcript with course codes, letter grades, and credit hours — the exact format CASPA processes for any other regionally accredited university course.
Critically for refresh-stage applicants, this means there is no “is it accepted?” anxiety. PA programs do not need to evaluate a new institution they have never heard of. They evaluate an Upper Iowa University transcript exactly the way they would evaluate a transcript from any state university. The administrative friction is zero.
PrereqCourses uses rolling enrollment and rolling completion. You can start any course on any day. You can finish in six to ten weeks if you work intensively, or take the full sixteen-week term if you need more time. Each course is self-contained — there is no semester schedule to wait for, no fall-spring-summer sequencing that forces multiple academic years to complete a four-course refresh.
This is decisive for refresh-stage applicants. A working career changer can complete A&P I in August–September, A&P II in October–November, Microbiology in December–January, and General Chemistry I in February–March — finishing the bulk of a refresh in roughly eight months on weekends and evenings, without quitting their current job.
A&P, Microbiology, General Biology, and General Chemistry all include physical home lab kits — anatomical models for A&P, culturing supplies and a small incubator for Microbiology, reagents and glassware for Chemistry, microscopy materials for Biology. The lab component transcribes as part of the course; CASPA processes the credit identically to in-person labs.
The most commonly refreshed courses, with direct links:
Check the recency policy on each target program’s prerequisite page. The wording typically says something like “science prerequisites must be completed within X years.” Measure from your course completion date to the program’s matriculation date for the strictest standard. If a program’s prerequisite page does not mention recency, assume there is no recency rule — but verify by email if you are unsure.
No. Roughly 45% of CASPA-participating programs do not apply any recency rule to prerequisite coursework. Roughly 20% apply a 10-year rule, 20% apply a 7-year rule, and 15% apply a 5-year rule. If your target list is weighted toward the 45% with no recency rule, you may not need to refresh at all.
Lab science courses — Anatomy & Physiology, Microbiology, General Chemistry, Organic Chemistry, Biochemistry, and General Biology — are the courses programs most consistently treat as expiring. Non-lab courses like Statistics, Psychology, English Composition, and Medical Terminology rarely have recency requirements applied to them.
Yes. The overwhelming majority of CASPA-participating PA programs accept online prerequisite coursework — including lab sciences — from regionally accredited US institutions. Online refreshes appear on CASPA transcripts identically to in-person coursework. See our pillar guide on online PA prerequisite acceptance for the full landscape.
Mechanically, yes. A refresh is a full credit-bearing course retaken at an accredited institution with a letter grade. PA programs do not distinguish between “refresh” (where the original course was simply old) and “retake” (where the original grade was low) — both are processed by CASPA as additional course completions in the same prerequisite category.
Yes. CASPA does not remove or hide prior course attempts. Both the original (now-expired) course and the new refresh course appear on your transcript, and both grades count in your prerequisite GPA. For refresh-stage applicants, this is usually beneficial — most original grades are reasonable and the new high grade from the refresh further raises your prereq GPA.
You can refresh as few or as many as your application strategy requires. Many refresh-stage applicants need only A&P I and II refreshed, plus possibly Microbiology, because those are the most-recency-restricted prerequisites at most programs. General Biology and General Chemistry are sometimes accepted as older coursework even at programs that require recent A&P and Micro. Audit each target program to determine the minimum refresh set.
A typical four-course refresh takes 6–8 months of part-time work using self-paced online prerequisite coursework. A six-course refresh takes 8–10 months. In contrast, the same work at a traditional community college takes 18–24 months due to semester scheduling. Self-paced enrollment is decisive for refresh-stage applicants on a CASPA timeline.
Both are usually acceptable. The exception is a minority of competitive PA programs (typically the top 20–30) that prefer prerequisite coursework from a four-year institution. PrereqCourses.com is delivered through Upper Iowa University — a four-year regionally accredited university — which clears this bar at programs where community college coursework might not.
Sometimes. The treatment of AP credits varies by program. Some programs accept AP credit for prerequisite purposes regardless of how old the original exam was. Some programs do not accept AP credit at all for science prerequisites. Some accept AP credit but apply the same recency rule that applies to college coursework. Verify on each program’s prerequisite page.
Expired prerequisites are not a disaster. They are a project — a defined, finite, mechanical project — and refresh-stage applicants who treat them that way succeed reliably. The framework is consistent across thousands of refresh-stage applications: audit your transcript against each target program’s recency rule, identify the minimum set of refresh courses your application strategy requires, and execute on a compressed self-paced timeline that finishes well before the next CASPA cycle.
Most refresh-stage applicants discover, once they have done the audit, that they need to refresh four to six courses to compete at their target programs — almost always centered on A&P, Microbiology, and General Chemistry. With self-paced online prerequisite coursework, that refresh is a six-to-ten-month project, not a multi-year one. The applicants who delay because they assume the refresh will take two years are giving up cycles for no reason.
If you are 30, 35, or 40, and you have a strong undergraduate science background that has aged out of CASPA recency rules, you are not starting over. You are completing a tightly scoped retake project that brings your existing strong record forward into a new application cycle.
| Ready to start refreshing? Browse the PA school prerequisite course catalog at PrereqCourses.com. All courses are delivered through Upper Iowa University — regionally accredited, lab kits included, self-paced, with rolling enrollment. Most refresh-stage applicants can finish their first course in six to ten weeks while keeping their current job. |
Not sure which of your old prerequisites need refreshing? Speak with an academic advisor — we’ll pull your transcript, audit it against your target program list, and identify the exact minimum refresh set your strategy requires.
