RT Prerequisite Recency Rules: The 5-Year Window Explained- why respiratory therapy programs put a time limit on science prerequisites, how to tell if your credits have expired, and how to refresh them.
You took anatomy and physiology years ago, you passed it, and the credit is right there on your transcript. So it still counts toward respiratory therapy school — right? Not always. Many RT programs put a time limit on science prerequisites, and a course that’s too old may not satisfy the requirement no matter how well you did. If you’re returning to school after a gap, this is one of the most important — and most overlooked — rules to check.
This guide explains the prerequisite recency rules respiratory therapy programs use, why science courses in particular have an expiration date, how to figure out whether your credits are still valid, and how to refresh them if they’ve aged out. You can look up specific accredited programs and their policies through the Commission on Accreditation for Respiratory Care (CoARC).
Short answer: Many respiratory therapy programs require science prerequisites — biology, anatomy and physiology, chemistry, microbiology — to have been completed within a recent window, most commonly the last 5 years, though some allow up to 10 and a few set no limit at all. If your science credits fall outside your target program’s window, the usual fix is to retake the affected courses, which also refreshes your knowledge and can strengthen your prerequisite GPA.
It can feel unfair that a course you passed no longer counts. But the logic behind recency rules is straightforward: in fast-moving scientific fields, knowledge ages. Programs want incoming students to arrive with current science, not concepts learned a decade or more ago, because the prerequisite material is the foundation they build clinical training on.
This is why the rules fall hardest on science courses:
Math and medical terminology tend to be treated more leniently, because the content changes far less. The recency concern is concentrated on the sciences.
There is no single national rule — recency policies vary by program, and the variation is wide. Here are the common patterns you’ll encounter:
| Policy type | What it looks like |
|---|---|
| 5-year window (most common) | Science prerequisites must be completed within 5 years of application. Older credit must be retaken. |
| 10-year window | A more generous limit some programs use; science is preferred within the last 10 years. |
| Graduated / points-based | No hard cutoff, but recent courses earn more admission points than older ones — so age weakens, rather than disqualifies, an application. |
| No expiration | Some programs place no time limit on prerequisite credit, especially courses taken at the same institution. |
| Science-only | The window applies to biology, chemistry, A&P, and microbiology, while math and general-education courses are exempt or treated more loosely. |
Two details matter when you read a policy. First, check the reference point: the clock usually runs to the application deadline (or program start), not to today. Second, check exactly which courses the rule covers — many programs apply it only to the sciences.
If your program has a recency rule, it will almost certainly apply to your science prerequisites. Here’s how the common courses typically fare, with links to each course guide:
The pattern is clear: the older your science prerequisites are, the more likely they’ll need refreshing — while non-science prerequisites usually travel with you regardless of age.
Before you assume anything — good or bad — work through these steps for each program on your list:
If everything falls inside the window, you’re set. If not, the fix is usually simpler and faster than people expect.
When a science prerequisite has aged out, retaking it is the standard solution — and it does more than just reset the clock:
The practical path is to retake the affected courses online, self-paced, through a regionally accredited institution — credit that respiratory therapy programs accept for transfer. That’s exactly what the RT Science Prerequisite Bundle is built for: refresh anatomy and physiology, microbiology, or chemistry on your own timeline, on one accredited transcript, before your application window. Confirm regional accreditation matters here — most programs require prerequisites from a regionally accredited institution to transfer.
Do respiratory therapy prerequisites expire?
At many programs, yes — science prerequisites often must be completed within a recent window, most commonly 5 years. But policies vary: some allow up to 10 years, some use a points system, and a few set no limit. Check each program.
Which courses are affected by the time limit?
Usually the sciences — biology, anatomy and physiology, chemistry, and microbiology. Math and medical terminology are frequently exempt or treated more leniently, because their content changes little.
Does the 5-year window count to today or to my application?
Typically to the application deadline or program start date, not to the current moment. Count back from the program’s reference point, and watch for courses that will age out before your intended cycle.
What if my A&P or microbiology credit is expired?
The standard fix is to retake the course. A fresh completion satisfies the recency rule, refreshes the knowledge, and — where programs count the highest attempt — can also improve your prerequisite GPA.
Can I retake an expired prerequisite online?
Yes. Retaking online and self-paced through a regionally accredited institution is a common, flexible way to refresh expired science credit before applying. Confirm your program accepts the format, including any lab.
Do all programs have a recency rule?
No. Some programs place no expiration on prerequisite credit. Because the rules vary so widely, always confirm the specific policy with each program you’re considering.
If you’re returning to school after a gap, prerequisite recency rules are one of the first things to check — a passed course isn’t always a current one. Most programs apply a window (often 5 years) to science prerequisites, and the fix for expired credit is simply to retake it, which refreshes your knowledge and can lift your prerequisite GPA at the same time. After you graduate from a CoARC-accredited program, the National Board for Respiratory Care (NBRC) administers the exams that lead to credentialing and licensure — so arriving with current, solid science serves you well beyond admission. (For a sense of how in-demand the field is, the American Association for Respiratory Care (AARC) reports strong, growing demand for respiratory therapists.)
Need to refresh expired credit? Use the RT Science Prerequisite Bundle — self-paced, online, regionally accredited courses to retake anatomy and physiology, microbiology, or chemistry on your timeline. Confirm each program’s recency policy and reference date with its admissions office before you decide what to retake.
Plan and refresh your prerequisites with confidence:
Recency windows, which courses they cover, reference dates, retake policies, and exceptions vary widely by institution and change over time. This guide is for general information only. Always confirm the specific policy directly with the respiratory therapy program you intend to apply to.
