How Many Biology Credits Do You Need for PA School- the direct answer, the BCP total-credit rules, and the upper-division biology requirements that move competitive applicants from ‘qualified’ to ‘admitted’
| THE DIRECT ANSWERMost CASPA programs require 8 semester credits of General Biology with lab — typically Biology I and Biology II, each 4 credits including a lab. This is the universal baseline. Competitive programs add upper-division biology requirements on top: Microbiology, Genetics, Cell Biology, Molecular Biology, Immunology, or similar — usually 3–6 additional credits. OHSU requires a minimum of 30 BCP (Biology, Chemistry, Physics) semester credits total. Temple requires ‘2 or more courses’ from a named upper-level biology list. Most strong applicants end up with 16–24 biology credits on their transcript. |
This guide unpacks the credit-counting rules that determine whether your transcript clears your target programs — including the ‘what doesn’t count’ rules that catch applicants (Ecology and Evolution courses, mammalian anatomy, animal physiology), the BCP credit-minimum thresholds, and the upper-division biology decisions that separate admitted from waitlisted applicants.
Almost every CASPA program requires the same biology baseline: two semesters of General Biology, each with a lab, for a total of 8 semester credits (or 12 quarter credits). The course typically appears on a transcript as:
Total: 8 semester credits. This is the floor — the bare minimum that satisfies the general biology prerequisite at virtually every program in the CASPA system.
Programs want applicants who have completed a full year of college-level biology instruction with hands-on lab experience. Two semesters cover the foundational sequence — cell biology, biochemistry of life, genetics, evolution, animal/plant biology — at depth that one semester can’t deliver. The lab component, even online, demonstrates that applicants have performed actual scientific procedures rather than just absorbing concepts.
If your courses are in quarter credits, divide by 1.5 to convert to semester credits. CASPA does this conversion automatically. The example often used: 4 quarter credits = 2.67 semester credits, so a 4-quarter-credit biology course doesn’t satisfy a 3-semester-credit minimum. Watch for this if your undergrad was on the quarter system — credits don’t translate one-to-one.
This is where applicants get caught. Programs are specific about what kind of biology counts for the General Biology I & II requirement — and several common course types fail.
| TUFTS’ ECOLOGY/EVOLUTION RULETufts University School of Medicine PA program states: ‘Ecology and Evolution courses will not be accepted for Biology I & II with lab pre-requisite requirements.’ This rule generalizes informally to many programs. General Biology should focus on cellular and molecular biology, genetics basics, and animal physiology — not ecosystem dynamics or evolutionary theory. If your General Biology sequence was titled ‘Ecology and Evolution’ or focused on those topics, plan to take an additional general biology course to clear strict programs. |
OHSU’s PA program excludes a broader set of biology subspecialties from counting toward the BCP minimum: ‘Plant, marine, environmental, exercise science/kinesiology, nutrition, etc. coursework will not be counted towards the minimum credit requirement.’ If you majored in marine biology or environmental science, your biology credits may not count toward the BCP minimum at programs with this rule — only your human-/animal-focused biology will.
Courses with titles like ‘Biology for Non-Majors,’ ‘Conceptual Biology,’ or ‘Biology of Human Affairs’ are usually rejected at PA programs. These courses are designed for general education credit and don’t cover the cellular and molecular content science majors need. PA programs almost universally require General Biology designed for science majors. If your existing biology credit is from a non-majors course, plan to take a science-majors-level biology course to clear the requirement.
Mixed acceptance. Some programs accept AP Biology with a score of 4 or 5; many reject AP credit for science prerequisites regardless of score. USC Keck’s PA program has an interesting middle ground: if AP credit is awarded for one semester of biology, the applicant must either complete a full two-semester biology sequence or complete 6 semester units (about two upper-division biology courses) to fully satisfy the requirement. Verify each target program before assuming AP biology counts.
The 8-credit baseline gets you past programs at the bottom of the requirement spectrum. Competitive programs want more — specifically, named upper-division biology courses that demonstrate readiness for graduate-level science.
Temple’s Lewis Katz School of Medicine PA program lists General Biology I & II among its baseline science prereqs, then adds:
| TEMPLE’S UPPER-LEVEL BIOLOGY REQUIREMENTTemple PA published requirement: ‘2 or more courses from the following list: Genetics, Molecular Biology, Immunology, Microbiology…’ Temple requires upper-level biology beyond the General Biology baseline — at minimum two additional named courses. This is a common pattern at competitive programs: General Biology is the floor; upper-level biology demonstrates real readiness. |
Rutgers’ PA program requires applicants to complete additional upper-level biology beyond the General Biology I & II baseline. The program publishes specific guidance: ‘When considering which courses to choose, we suggest the following: genetics, microbiology, immunology, cell biology, and biochemistry.’ Two courses from this list satisfy the additional biology requirement.
Duke’s PA program recommends (without requiring) additional biological science coursework beyond the baseline: ‘To fulfill the other biological science course prerequisites, the PA Program recommends courses in genetics, cell biology, molecular biology, embryology, histology, or immunology.’ At competitive programs like Duke, the recommendation functions like a soft requirement — applicants who skip it are at a meaningful disadvantage.
Across competitive CASPA programs, five upper-division biology courses appear most frequently in ‘recommended’ or ‘required’ lists:
Plus Biochemistry — which is increasingly required as a separate chemistry prerequisite but also counts toward biology rigor in admissions review.
Some programs go further and require a minimum total credit count across Biology, Chemistry, and Physics — the BCP categories CASPA uses to calculate one of the GPAs admissions committees track.
| OHSU’S BCP MINIMUMOHSU’s PA program states: ‘Total Biology, Chemistry, and/or Physics (BCP) Credits — Minimum of 30 semester credits or 40 quarter credits are required. Includes all coursework taken in the biology, chemistry, and/or physics departments that are medically, human, and/or animal science related.’ This is the headline rule the article exists to answer. OHSU wants 30 BCP credits — biology + chemistry + physics combined — with the explicit qualifier that the coursework must be medically/human/animal-focused. The same coursework rules that exclude ecology and plant biology apply to this credit count. |
Here’s how a competitive applicant accumulates 30 BCP semester credits across biology, chemistry, and physics:
| Course | Semester Credits | Category |
|---|---|---|
| General Biology I + lab | 4 | Biology |
| General Biology II + lab | 4 | Biology |
| Microbiology + lab | 4 | Biology |
| Anatomy & Physiology I + lab | 4 | Biology |
| Anatomy & Physiology II + lab | 4 | Biology |
| General Chemistry I + lab | 4 | Chemistry |
| General Chemistry II + lab | 4 | Chemistry |
| Biochemistry | 3 | Chemistry |
| Genetics (or other upper-level bio) | 3 | Biology |
| TOTAL BCP CREDITS | 34 | Biology: 23, Chem: 11 |
This stack — General Biology I/II, A&P I/II, Microbiology, General Chem I/II, Biochem, and one upper-level biology — clears OHSU’s 30-BCP-credit minimum with a small buffer. Most applicants whose target list includes competitive programs end up with this stack or a similar one.
Here’s how seven CASPA programs handle biology credit requirements:
| Program | Baseline | Upper-Level Bio | Other Rules |
|---|---|---|---|
| OHSU | Gen Bio + lab | Recommended (300/400-level) | 30 total BCP semester credits required (hard floor) |
| Temple LKSOM | Gen Bio I & II + labs (8 credits) | 2+ courses from named list (required) | Genetics, Molecular Bio, Immunology, Microbiology, etc. |
| Rutgers | Gen Bio I & II + labs | Additional Upper-Level Bio (required) | Suggested: genetics, microbiology, immunology, cell bio, biochem |
| Duke | Gen Bio sequence | Recommended (‘other bio sciences’) | Genetics, cell bio, molecular bio, embryology, histology, immunology |
| Wake Forest | Gen Bio + lab | Genetics required separately | Molecular-based genetics specifically; social genetics rejected |
| Tufts PA | Gen Bio I & II + labs | Upper-level options listed | Ecology/Evolution EXPLICITLY EXCLUDED from baseline |
| Yale Physician Associate | Gen Bio + lab | Strongly encouraged | ‘Any upper-level biology courses will only help enhance your application’ |
A confusing point for applicants: courses like Anatomy & Physiology, Microbiology, and Genetics are often listed as separate prerequisites — but they also count toward the broader ‘biology credits’ category. Two questions to answer:
Yes, generally. If your transcript shows BIO 270 Anatomy & Physiology I (4 credits) under the Biology department, those 4 credits count toward:
This is why building out your biology stack with named upper-level courses (Microbiology, A&P I/II, Genetics) is so efficient — each course clears a named prerequisite AND contributes to your total BCP credit count.
Watch for this. Some institutions offer A&P through Nursing, Allied Health, or Health Sciences departments. The course content may be identical, but the transcript line under a non-Biology department changes how CASPA categorizes it. Programs like Colorado-Anschutz that require ‘science majors only’ coursework may reject non-Biology-department A&P entirely. Programs that require BCP credit minimums may not count it toward Biology.
The PrereqCourses solution: all biology-relevant prerequisites — BIO 135 Principles of Biology I, BIO 210 Microbiology w/ Lab, BIO 270 Anatomy & Physiology I, BIO 275 Anatomy & Physiology II, BIO 282 Genetics, and BIO 165 Human Biology & Nutrition — appear on the Upper Iowa University transcript with the BIO department designation. They count toward biology credit totals at programs that calculate them.
You have the 8-credit baseline. For programs at the bottom of the requirement spectrum, you’re set. For competitive programs (Duke, Wake Forest, Yale, Rutgers, Temple), you need to add upper-level biology. Plan to add at least: BIO 210 Microbiology w/ Lab (4 credits, satisfies Microbiology prereq + adds to biology total) and BIO 282 Genetics (3 credits, satisfies Genetics prereq at programs that require it + adds to biology total). That brings you to 15 biology credits, comfortably within competitive territory.
Tufts will reject this for the Biology I & II requirement, and many programs apply similar logic informally. Plan to add at least one general biology course for science majors. BIO 135 Principles of Biology I w/ Lab is structured as the first course in a two-course introductory biology sequence for biological sciences majors — it satisfies the science-majors-level requirement and adds 4 credits to your biology total.
Map your existing BCP credits against the 30-credit minimum. If you’re at 22 BCP credits with General Biology I/II, Gen Chem I/II, and A&P I/II, you need 8 more. Add: BIO 210 Microbiology w/ Lab (4 credits) + BIO 282 Genetics (3 credits) + CHEM 330 Biochemistry I (3 credits) = 10 additional BCP credits, bringing you to 32. Clears OHSU’s 30-credit floor with a buffer.
Wake Forest recommends repeating any prerequisite from before 2021. If your General Biology is from 10+ years ago, plan a refresh. A single BIO 135 Principles of Biology I gives you a recent biology grade and re-anchors your transcript. Pair it with BIO 282 Genetics or BIO 210 Microbiology to demonstrate continued biology engagement.
Aim for 16–24 biology credits with strategic course choices. A common high-leverage stack: General Biology I/II (8) + A&P I/II (8) + Microbiology (4) + Genetics (3) = 23 biology credits, all CASPA-categorized as biology, all clearing named prerequisites at competitive programs. Add Biochemistry (3) for the BCP total, and you’re at 26 biology credits + significant chemistry. This is the profile competitive programs look for.
Three realistic biology credit strategies for PA applicants:
| Strategy | Total Biology Credits | Programs Cleared | Notes |
|---|---|---|---|
| Minimum baseline only | 8 credits | Lower-tier programs | Gen Bio I & II only; fails competitive programs |
| Baseline + A&P | 16 credits | Most programs | Gen Bio + A&P I/II; satisfies standard prereq lists |
| Competitive profile | 23 credits | Competitive programs | Adds Microbiology + Genetics for upper-level bio coverage |
| Strict-program profile | 26+ credits + 30 BCP | All programs incl. OHSU, Temple | Adds Biochem and additional upper-level bio elective |
CASPA uses the granting institution’s department coding to categorize coursework. A course from a Biology department codes as Biology and counts toward the Biology subject area in your CASPA profile. The Biology subject area feeds into:
Across competitive 2026–2027 PA programs, the BCP GPA carries more weight in admissions decisions than the overall GPA. Programs are looking for a BCP GPA of 3.5 or higher to consider a candidate highly competitive. A strong grade in upper-level biology (Genetics, Microbiology, Cell Biology) lifts the BCP GPA more proportionally than a strong grade in intro biology because the upper-level grade carries more informational weight per credit hour.
| BIO DEPARTMENT DESIGNATION IS THE GOALAll biology-relevant PrereqCourses courses appear on the Upper Iowa University transcript with the BIO department designation. This matters because programs like Colorado-Anschutz reject coursework from Nursing, Allied Health, Kinesiology, Exercise Science, and Nutrition departments — even when the content is biology. UIU’s Biology department coding clears these strict-department-source rules automatically. |
8 semester credits of General Biology with lab — two semesters, each 4 credits including a lab. This is the universal baseline. Programs at the bottom of the requirement spectrum accept this. Competitive programs want more.
Yes, if it’s offered through a Biology department. A&P I and II together typically add 8 biology credits to your transcript (4 each, including labs). These count toward your biology total and your BCP credit count at programs with that requirement.
Yes, at virtually all programs — as long as it’s offered through a Biology department. Microbiology typically adds 4 biology credits (3 lecture + 1 lab) to your transcript. It’s the highest-value single course you can add to a transcript that lacks upper-level biology, because it clears both the named Microbiology prerequisite and contributes to biology totals.
Chemistry, almost always. Biochemistry is categorized under Chemistry at most institutions even when the content overlaps biology. Tufts notes this explicitly: ‘Will be considered a chemistry course unless categorized as a biology course by the granting institution on the transcript.’ At Upper Iowa University, CHEM 330 Biochemistry I is in the Chemistry department — so it counts toward chemistry credits, not biology credits, but does count toward the BCP total.
Two named upper-level biology courses, at minimum, beyond General Biology I & II. Temple requires ‘2 or more.’ Rutgers requires ‘additional upper-level biology’ (interpreted as two courses). Duke recommends a similar set. Most competitive applicants build to 3–4 upper-level biology courses to differentiate themselves.
Probably yes, but verify. A biology major typically accumulates 30–40 biology credits over the course of the degree, easily clearing all PA program biology requirements. Watch for two issues: (1) some of those credits may be in subspecialties that don’t count (ecology, plant biology, marine biology), and (2) your major may not include named PA prereqs like Microbiology or A&P. Map your transcript against each target program’s named prerequisite list.
Often yes. Additional upper-level biology beyond the minimum lifts your BCP GPA, demonstrates academic rigor, and adds informational weight to your application. The diminishing returns kick in around 26–28 biology credits — past that, additional biology courses help less than other application investments (clinical hours, GRE prep, personal statement quality).
Biology credits for PA school are a layered question. The 8-credit baseline is universal. The 16-credit standard profile (baseline + A&P) clears most programs. The 23–26 credit competitive profile clears all programs and lifts your BCP GPA into competitive territory. Where on the spectrum you need to land depends on which programs are on your target list.
| BUILD YOUR BIOLOGY CREDIT STACKPrereqCourses delivers the biology courses that build to competitive credit totals: BIO 135 Principles of Biology I, BIO 210 Microbiology w/ Lab, BIO 270 / BIO 275 Anatomy & Physiology I & II, BIO 282 Genetics, and CHEM 330 Biochemistry I. Each $675, 3–4 credits, transcripted by Upper Iowa University with the appropriate BIO or CHEM department designation. The full stack costs roughly $4,000 — dramatically less than the state university equivalent — and brings most applicants from baseline to competitive profile in a single application cycle. |
View all biology courses | BIO 210 Microbiology | BIO 282 Genetics | Speak with an advisor
