The American Association of Colleges of Osteopathic Medicine Application Service (AACOMAS®) is the centralized application system for all U.S. osteopathic (DO) medical schools. If you are applying to DO programs, either exclusively or alongside MD programs through AMCAS®, you will use AACOMAS®. While the two systems are similar in structure, there are important differences in GPA calculation, timeline, and application content that affect your strategy. This page covers the AACOMAS® application in detail, with emphasis on the features that distinguish it from AMCAS®. For the MD application, see our AMCAS® guide. For a comparison of MD and DO training, see our MD vs. DO page.
Key Differences from AMCAS
Grade Replacement: The single most important difference between AACOMAS® and AMCAS® is grade replacement. AACOMAS® uses only the most recent grade when you retake a course, effectively replacing the original grade in your GPA calculation. AMCAS® does not offer grade replacement; both the original and retake grades are included. This policy makes DO programs particularly accessible for students who had early academic difficulties and subsequently demonstrated improvement. If you earned a C in General Chemistry during freshman year, retook it junior year and earned an A, AACOMAS® uses only the A. AMCAS® averages both grades. For students with significant grade improvements through retaken courses, the AACOMAS® GPA can be substantially higher than the AMCAS® GPA.
Personal Statement: The AACOMAS® personal statement has a 5,300-character limit, identical to AMCAS®. However, DO programs expect your personal statement to address why you are specifically interested in osteopathic medicine, not just medicine in general. If you are submitting both AMCAS® and AACOMAS® applications, you should write two versions of your personal statement: one for MD programs and one that includes specific discussion of your interest in osteopathic philosophy, osteopathic manipulative medicine, and the whole-person approach to patient care that defines DO education. A personal statement that makes no mention of osteopathic medicine signals to DO admissions committees that you view their school as a backup rather than a genuine choice.
Experiences Section: AACOMAS® allows you to describe experiences in categories similar to AMCAS® but with some different labeling and structure. You can list clinical experiences, research, community service, leadership, shadowing, and other activities. AACOMAS® does not have a “Most Meaningful” designation like AMCAS®, but you should still prioritize your strongest and most reflective descriptions in the activities you list first.
Demonstrating Interest in Osteopathic Medicine
DO admissions committees want to see that your interest in osteopathic medicine is genuine and informed. The most effective ways to demonstrate this interest are shadowing DO physicians (ideally including observation of osteopathic manipulative treatment in practice), articulating specific aspects of osteopathic philosophy that resonate with you (the holistic approach, the emphasis on the musculoskeletal system, the focus on prevention and wellness), explaining how osteopathic principles align with your clinical experiences and your vision for your practice, and demonstrating knowledge of how DO education differs from MD education (OMM coursework, the COMLEX-USA® licensing exam sequence, the osteopathic medical school curriculum). Do not write generic statements about “treating the whole patient.” Be specific about which aspects of osteopathic philosophy you have observed in practice, which OMT techniques you have seen used, and how the osteopathic approach would shape the kind of physician you want to become. See our DO pathway page for background on osteopathic medicine.
Timeline
The AACOMAS® cycle runs roughly parallel to AMCAS® but with slightly different dates. The application typically opens for submission in early May (sometimes a few days before AMCAS®). Early submission is just as important for DO programs as for MD programs, because many DO schools use rolling admissions. Verification typically takes 2 to 4 weeks. Secondary applications from individual DO schools begin arriving shortly after verification. Interview invitations are sent on a rolling basis from August through March. Acceptance notifications are also rolling, with the earliest coming in October. As with MD applications, submitting early maximizes your chances because more interview slots and acceptance positions are available early in the cycle.
School List Strategy for DO Programs
There are approximately 40 osteopathic medical schools in the United States, with new campuses opening regularly. When building your DO school list, consider geographic location and your willingness to relocate, the school’s clinical rotation sites and affiliated hospitals (DO schools vary widely in the quality and diversity of their clinical training), the school’s residency match rate and specialty distribution, tuition and financial aid, the school’s emphasis on primary care versus specialty training, and whether the school has a focus area that aligns with your interests (rural health, community medicine, research, military medicine). Apply to 8 to 15 DO programs with a balanced mix of reach, target, and safety schools based on median MCAT® and GPA data available on each school’s website and in AACOM publications.
Applying to Both MD and DO Programs
Many applicants submit both AMCAS® and AACOMAS® applications to maximize their chances of acceptance. This is a sound strategy, but it requires managing two parallel application processes with different timelines, different personal statements, and different school lists. Budget additional time and money for the dual application: AACOMAS® charges a primary application fee plus per-school fees, and each DO school sends its own secondary application with additional fees. If cost is a concern, the AACOM Fee Waiver Program provides fee reductions for qualifying applicants. Applying broadly across both MD and DO programs gives you the best chance of receiving at least one acceptance, and you can make your final decision about which school to attend after comparing all offers.
For the AMCAS® process, see our AMCAS® guide. For secondary essays, see our secondary applications page. For interview preparation, see our interview preparation page.
Letters of Recommendation for DO Schools: AACOMAS® allows you to assign specific letters to specific schools, which means you can tailor your letter set to each program. Most DO schools require 2 to 3 letters, and many specifically request a letter from a DO physician. If you have shadowed or worked with a DO physician, asking them for a letter demonstrates genuine engagement with osteopathic medicine. If you do not have a DO letter, a letter from an MD physician who can speak to your clinical engagement is acceptable at most schools, but check each school’s specific requirements. Having at least one letter that speaks to your understanding of and interest in osteopathic philosophy strengthens your DO application.
Supplemental Applications for DO Schools: Like MD schools, individual DO programs send secondary (supplemental) applications after your AACOMAS® primary is verified. DO secondary prompts often include questions about your interest in osteopathic medicine, your understanding of OMM, and why you are drawn to their specific program. Pre-write responses to common DO secondary prompts during the waiting period after primary submission, using the same strategy described in our secondary applications page. Be specific about each school’s programs, clinical training sites, and community focus in your “why our school” essays. DO schools are community-focused institutions, and demonstrating knowledge of and commitment to the communities they serve strengthens your candidacy.
AACOMAS GPA Calculation in Detail: AACOMAS® calculates several GPAs: cumulative, science (BCP: biology, chemistry, physics), non-science, and total. The BCP GPA is the most scrutinized by DO admissions committees. Unlike AMCAS®, AACOMAS® uses grade replacement for repeated courses: only the most recent grade is included in the GPA calculation. This means if you retook 3 courses and improved each by one letter grade, your AACOMAS® GPA could be 0.2 to 0.4 points higher than your AMCAS® GPA. Use the AACOMAS® GPA calculator (available on the AACOM website) to verify your GPA before submitting. If grade replacement significantly improves your GPA, make sure your school list includes enough DO programs to take advantage of this benefit.
References
American Association of Colleges of Osteopathic Medicine (AACOM). “AACOMAS.” AACOM, 2025. https://www.aacom.org/. Accessed March 2026.