| College Board | 501(c)(3) | New York, NY | $983 million |
| National Education Association of the United States | 501(c)(5) | Washington, DC | $396 million |
| United States PHARMACOPEIAL Convention (USP) | 501(c)(3) | Rockville, MD | $342 million |
| Project Management Institute (PMI) | 501(c)(6) | Newtown Square, PA | $329 million |
| National Association of Realtors | 501(c)(6) | Chicago, IL | $327 million |
| CFA Institute | 501(c)(6) | Charlottesville, VA | $299 million |
| College of American Pathologists (CAP) | 501(c)(6) | Northfield, IL | $258 million |
| United States Golf Association (USGA) | 501(c)(3) | Liberty Corner, NJ | $231 million |
| Society for Human Resource Management (SHRM) | 501(c)(6) | Alexandria, VA | $173 million |
| American College of Surgeons (ACS) | 501(c)(3) | Chicago, IL | $148 million |
| American Dental Association (ADA) | 501(c)(6) | Chicago, IL | $138 million |
| American Hospital Association | 501(c)(6) | Chicago, IL | $128 million |
| American Academy of Pediatrics (AAP) | 501(c)(3) | Itasca, IL | $127 million |
| National Football League Players Association (NFLPA) | 501(c)(5) | Washington, DC | $107 million |
| American Association for Cancer Research | 501(c)(3) | Philadelphia, PA | $103 million |
| American College of Physicians (ACP) | 501(c)(3) | Philadelphia, PA | $101 million |
| American Society of Mechanical Engineers (ASME) | 501(c)(3) | New York, NY | $95 million |
| Association of Public Health Laboratories | 501(c)(3) | Silver Spring, MD | $89 million |
| American Society of Hematology (ASH) | 501(c)(3) | Washington, DC | $89 million |
| American National Standards Institute (ANSI) | 501(c)(3) | New York, NY | $89 million |
| California Academy of Sciences | 501(c)(3) | San Francisco, CA | $88 million |
| American Bar Association (ABA) | 501(c)(6) | Chicago, IL | $86 million |
| American Physical Society | 501(c)(3) | College Park, MD | $83 million |
| American Institute of Physics (AIP) | 501(c)(3) | College Park, MD | $82 million |
| American Academy of Family Physicians | 501(c)(6) | Leawood, KS | $80 million |
| American Speech-Language-Hearing Association (ASHA) | 501(c)(6) | Rockville, MD | $70 million |
| Radiological Society of North America (RSNA) | 501(c)(3) | Oak Brook, IL | $68 million |
| American Society of Civil Engineers (ASCE) | 501(c)(3) | Reston, VA | $62 million |
| The Institute of Internal Auditors (IIA) | 501(c)(6) | Lake Mary, FL | $59 million |
| American Society of Anesthesiologists (ASA) | 501(c)(6) | Schaumburg, IL | $57 million |
| Association for Computing Machinery | 501(c)(3) | New York, NY | $56 million |
| American Society of Health-System Pharmacists (ASHP) | 501(c)(6) | Bethesda, MD | $56 million |
| American Psychiatric Association (APA) | 501(c)(6) | Washington, DC | $53 million |
| American Veterinary Medical Association (AVMA) | 501(c)(6) | Schaumburg, IL | $52 million |
| Optical | 501(c)(3) | Washington, DC | $51 million |
| American Academy of Orthopedic Surgeons (AAOS) | 501(c)(3) | Rosemont, IL | $50 million |
| Certified Financial Planner Board of Standards (CFP) | 501(c)(3) | Washington, DC | $49 million |
| American Health Care Association (AHCA) | 501(c)(6) | Washington, DC | $48 million |
| American Physical Therapy Association (APTA) | 501(c)(6) | Alexandria, VA | $48 million |
| American Academy of Ophthalmology (AAO) | 501(c)(6) | San Francisco, CA | $47 million |
| American Library Association (ALA) | 501(c)(3) | Chicago, IL | $46 million |
| The American Institute of Architects (AIA) | 501(c)(6) | Washington, DC | $44 million |
| American Urological Association Education and Research | 501(c)(3) | Linthicum Heights, MD | $41 million |
| Association for Talent Development | 501(c)(3) | Alexandria, VA | $39 million |
| American Academy of Dermatology | 501(c)(3) | Rosemont, IL | $38 million |
| National Council of Architectural Registration Boards (NCARB) | 501(c)(6) | Washington, DC | $34 million |
| National Association of County and City Health Officials (NACCHO) | 501(c)(3) | Washington, DC | $33 million |
| Association for Supervision and Curriculum Development | 501(c)(3) | Arlington, VA | $33 million |
| Association of periOperative Registered Nurses (AORN) | 501(c)(6) | Denver, CO | $33 million |
| American College of Gastroenterology (ACG) | 501(c)(3) | Bethesda, MD | $33 million |
| American Osteopathic Association (AOA) | 501(c)(3) | Chicago, IL | $32 million |
| Infectious Diseases Society of America (IDSA) | 501(c)(6) | Arlington, VA | $31 million |
| America's Blood Centers (ABC) | 501(c)(6) | Washington, DC | $31 million |
| American College of Rheumatology | 501(c)(6) | Atlanta, GA | $30 million |
| International Association of Chiefs of Police | 501(c)(3) | Alexandria, VA | $30 million |
| Pennsylvania Horticultural Society (PHS) | 501(c)(3) | Philadelphia, PA | $29 million |
| American Society for Quality | 501(c)(3) | Milwaukee, WI | $29 million |
| Oncology Nursing Society | 501(c)(6) | Pittsburgh, PA | $29 million |
| American Association of Nurse Anesthetists | 501(c)(6) | Park Ridge, IL | $28 million |
| American Dental Education Association | 501(c)(3) | Washington, DC | $28 million |
| National Association of Secondary School Principals (NASSP) | 501(c)(3) | Reston, VA | $28 million |
| Healthcare Information and Management Systems Society (HIMSS) | 501(c)(6) | Chicago, IL | $28 million |
| Endocrine Society | 501(c)(3) | Washington, DC | $28 million |
| American Gastroenterological Association Institute | 501(c)(3) | Bethesda, MD | $28 million |
| Association of the United States Army (AUSA) | 501(c)(3) | Arlington, VA | $27 million |
| American Society of Nephrology (ASN) | 501(c)(3) | Washington, DC | $27 million |
| American Society of Radiologic Technologists (ASRT) | 501(c)(6) | Albuquerque, NM | $27 million |
| American Association for Justice (AAJ) | 501(c)(6) | Washington, DC | $26 million |
| Texas Medical Association (TMA) | 501(c)(6) | Austin, TX | $26 million |
| International Citycounty Management Association | 501(c)(3) | Washington, DC | $25 million |
| American Association of Orthopaedic Surgeons (AAOS) | 501(c)(6) | Rosemont, IL | $24 million |
| Association of Social Work Boards | 501(c)(3) | Culpeper, VA | $24 million |
| Asis International | 501(c)(6) | Alexandria, VA | $24 million |
| Water Environment Federation (WEF) | 501(c)(3) | Alexandria, VA | $24 million |
| American Public Works Association | 501(c)(3) | Kansas City, MO | $24 million |
| Institute of Management Accountants | 501(c)(3) | Montvale, NJ | $24 million |
| American Institute of Aeronautics and Astronautics (AIAA) | 501(c)(3) | Reston, VA | $24 million |
| Global Business Travel Association (GBTA) | 501(c)(6) | Alexandria, VA | $24 million |
| Educause | 501(c)(3) | Boulder, CO | $23 million |
| American Retirement Association (ASPPA) | 501(c)(6) | Arlington, VA | $23 million |
| Society of Critical Care Medicine | 501(c)(3) | MT Prospect, IL | $23 million |
| Catholic Health Association of the United States | 501(c)(3) | Saint Louis, MO | $22 million |
| American Physiological Society (APS) | 501(c)(3) | Rockville, MD | $22 million |
| American College of Cardiology (ACC) | 501(c)(6) | Washington DC, DC | $22 million |
| Inteleos (ARDMS) | 501(c)(6) | Rockville, MD | $22 million |
| American College of Healthcare Executives (ACHE) | 501(c)(6) | Chicago, IL | $21 million |
| Council of Insurance Agents and Brokers | 501(c)(6) | Washington, DC | $21 million |
| American Society of Association Executives | 501(c)(6) | Washington, DC | $21 million |
| American Association of Nurse Practitioners | 501(c)(6) | Austin, TX | $21 million |
| Water For People | 501(c)(3) | Denver, CO | $21 million |
| American Occupational Therapy Association (AOTA) | 501(c)(6) | North Bethesda, MD | $20 million |
| Council of Chief State School Officers | 501(c)(3) | Washington, DC | $20 million |
| American Association of Colleges of Osteopathic Medicine (AACOM) | 501(c)(3) | Bethesda, MD | $19 million |
| AACSB International - The Association to Advance Collegiate Schools of Business (AACSB) | 501(c)(3) | Tampa, FL | $19 million |
| Physicians Committee for Responsible Medicine (PCRM) | 501(c)(3) | Washington, DC | $19 million |
| National Association for the Education of Young Children | 501(c)(3) | Washington, DC | $19 million |
| Drug Information Association | 501(c)(3) | Washington, DC | $18 million |
| American Society for Engineering Education | 501(c)(3) | Washington, DC | $18 million |
| American Society for Radiation Oncology (ASTRO) | 501(c)(6) | Arlington, VA | $18 million |
| Community Associations Institute (CAI) | 501(c)(6) | Falls Church, VA | $18 million |
| American Association of Blood Banks (AABB) | 501(c)(3) | Bethesda, MD | $17 million |
| American Society for Biochemistry and Molecular Biology | 501(c)(3) | Rockville, MD | $17 million |
| American Academy of Allergy, Asthma and Immunology (AAAAI) | 501(c)(3) | Milwaukee, WI | $17 million |
| American College of Radiology (ACR) | 501(c)(6) | Reston, VA | $17 million |
| Association of Community Cancer Centers (ACCC) | 501(c)(3) | Rockville, MD | $17 million |
| American Meteorological Society | 501(c)(3) | Boston, MA | $17 million |
| Council for Professional Recognition | 501(c)(3) | Washington, DC | $16 million |
| American Association for Clinical Chemistry (AACC) | 501(c)(3) | Washington, DC | $16 million |
| Academy of General Dentistry (AGD) | 501(c)(6) | Chicago, IL | $16 million |
| Association for the Advancement of Medical Instrumentation (AAMI) | 501(c)(6) | Arlington, VA | $16 million |
| Pharmacy Technician Certification Board (PTCB) | 501(c)(6) | Washington, DC | $16 million |
| Council of Independent Colleges (CIC) | 501(c)(3) | Washington, DC | $16 million |
| American Academy of Actuaries | 501(c)(6) | Washington, DC | $16 million |
| American Industrial Hygiene Association (AIHA) | 501(c)(6) | Falls Church, VA | $15 million |
| Academy of Management (AOM) | 501(c)(3) | Briarcliff Manor, NY | $15 million |
| Heart Rhythm Society (HRS) | 501(c)(3) | Washington, DC | $15 million |
| Casualty Actuarial Society (CAS) | 501(c)(6) | Arlington, VA | $15 million |
| American Association of Orthodontists | 501(c)(6) | Saint Louis, MO | $15 million |
| American Marketing Association | 501(c)(3) | Chicago, IL | $14 million |
| Association of Black Foundation Executives | 501(c)(3) | New York, NY | $13 million |
| International Association for the Study of Lung Cancer | 501(c)(3) | Denver, CO | $13 million |
| American Immigration Lawyers Association (AILA) | 501(c)(6) | Washington, DC | $13 million |
| Society of Women Engineers | 501(c)(3) | Chicago, IL | $13 million |
| International Society for Technology | 501(c)(3) | Portland, OR | $13 million |
| American Academy of Child and Adolescent Psychiatry | 501(c)(3) | Washington, DC | $13 million |
| Association of Women's Health Obstetric and Neonatal Nurses (AWHONN) | 501(c)(3) | Washington, DC | $13 million |
| American Counseling Association (ACA) | 501(c)(3) | Alexandria, VA | $13 million |
| Physician Assistant Education Association | 501(c)(3) | Washington, DC | $13 million |
| Association of Zoos and Aquariums | 501(c)(3) | Silver Spring, MD | $13 million |
| Association of Diabetes Care and Education Specialists | 501(c)(6) | Chicago, IL | $12 million |
| American Association of School Administrators (AASA) | 501(c)(3) | Alexandria, VA | $12 million |
| Council for Christian Colleges and Universities (CCCU) | 501(c)(3) | Washington, DC | $12 million |
| International Association of Fire Chiefs (IAFC) | 501(c)(3) | Chantilly, VA | $12 million |
| National League for Nursing | 501(c)(3) | Washington, DC | $12 million |
| Accreditation Board for Engineering and Technology | 501(c)(3) | Baltimore, MD | $12 million |
| Association for Corporate Growth | 501(c)(6) | Chicago, IL | $12 million |
| Risk and Insurance Management Society (RIMS) | 501(c)(6) | New York, NY | $12 million |
| Asm International | 501(c)(3) | Materials Park, OH | $12 million |
| Association for Professionals in Infection Control and Epidemiology | 501(c)(3) | Arlington, VA | $12 million |
| American Society of Addiction Medicine | 501(c)(3) | Rockville, MD | $11 million |
| National Pharmaceutical Council (NPC) | 501(c)(6) | Washington, DC | $11 million |
| American Educational Research Association | 501(c)(3) | Washington, DC | $11 million |
| Society of Nuclear Medicine and Molecular Imaging (SNMMI) | 501(c)(3) | Reston, VA | $11 million |
| Society of Interventional Radiology (SIR) | 501(c)(6) | Fairfax, VA | $11 million |
| Regulatory Affairs Professionals Society (RAPS) | 501(c)(3) | Rockville, MD | $11 million |
| Association for Corporate Growth - Group | 501(c)(6) | Chicago, IL | $11 million |
| American Council on the Teaching of Foreign Languages | 501(c)(3) | Alexandria, VA | $10 million |
| School Nutrition Association (SNA) | 501(c)(4) | Arlington, VA | $10 million |
| National Association of Student Financial Aid Administrators | 501(c)(3) | Washington, DC | $10 million |
| American Association of Collegiate Registrars and Admissions Officers | 501(c)(3) | Washington, DC | $9.9 million |