| Institute of Electrical and Electronics Engineers (IEEE) | 501(c)(3) | Piscataway, NJ | $566 million |
| National Education Association of the United States | 501(c)(5) | Washington, DC | $378 million |
| CFA Institute | 501(c)(6) | Charlottesville, VA | $346 million |
| United States Pharmacopoeial Convention (USP) | 501(c)(3) | Rockville, MD | $346 million |
| College of American Pathologists (CAP) | 501(c)(6) | Northfield, IL | $267 million |
| Project Management Institute (PMI) | 501(c)(6) | Newtown Square, PA | $267 million |
| Young Presidents' Organization (YPO) | 501(c)(6) | Irving, TX | $199 million |
| Society for Human Resource Management (SHRM) | 501(c)(6) | Alexandria, VA | $178 million |
| American Society of Mechanical Engineers (ASME) | 501(c)(3) | New York, NY | $160 million |
| American Dental Association (ADA) | 501(c)(6) | Chicago, IL | $138 million |
| American College of Surgeons (ACS) | 501(c)(3) | Chicago, IL | $129 million |
| American Academy of Pediatrics (AAP) | 501(c)(3) | Itasca, IL | $128 million |
| National Football League Players Association (NFLPA) | 501(c)(5) | Washington, DC | $123 million |
| American Society of Hematology (ASH) | 501(c)(3) | Washington, DC | $108 million |
| Council on Foreign Relations (CFR) | 501(c)(3) | New York, NY | $106 million |
| Association of Public Health Laboratories | 501(c)(3) | Silver Spring, MD | $101 million |
| Association for Computing Machinery | 501(c)(3) | New York, NY | $91 million |
| American Academy of Family Physicians | 501(c)(6) | Leawood, KS | $86 million |
| American Institute of Physics (AIP) | 501(c)(3) | College Park, MD | $81 million |
| National Association of County and City Health Officals (NACCHO) | 501(c)(3) | Washington, DC | $81 million |
| American College of Physicians (ACP) | 501(c)(3) | Philadelphia, PA | $75 million |
| California Academy of Sciences | 501(c)(3) | San Francisco, CA | $71 million |
| American Physical Society | 501(c)(3) | College Park, MD | $71 million |
| American Speech-Language-Hearing Association (ASHA) | 501(c)(6) | Rockville, MD | $68 million |
| American Society of Health-System Pharmacists (ASHP) | 501(c)(6) | Bethesda, MD | $66 million |
| American Academy of Ophthalmology (AAO) | 501(c)(6) | San Francisco, CA | $65 million |
| American Psychiatric Association (APA) | 501(c)(6) | Washington, DC | $64 million |
| The Institute of Internal Auditors (IIA) | 501(c)(6) | Lake Mary, FL | $64 million |
| American Society of Civil Engineers (ASCE) | 501(c)(3) | Reston, VA | $63 million |
| Radiological Society of North America (RSNA) | 501(c)(3) | Oak Brook, IL | $63 million |
| American Library Association (ALA) | 501(c)(3) | Chicago, IL | $61 million |
| Association of State and Territorial Health Officials | 501(c)(3) | Arlington, VA | $56 million |
| American Society of Anesthesiologists (ASA) | 501(c)(6) | Schaumburg, IL | $52 million |
| American Veterinary Medical Association (AVMA) | 501(c)(6) | Schaumburg, IL | $49 million |
| Certified Financial Planner Board of Standards (CFP) | 501(c)(3) | Washington, DC | $48 million |
| Association for Talent Development | 501(c)(3) | Alexandria, VA | $44 million |
| Optical | 501(c)(3) | Washington, DC | $44 million |
| American Physical Therapy Association (APTA) | 501(c)(6) | Alexandria, VA | $43 million |
| International Association of Chiefs of Police | 501(c)(3) | Alexandria, VA | $42 million |
| Association of periOperative Registered Nurses (AORN) | 501(c)(6) | Denver, CO | $42 million |
| American College of Gastroenterology (ACG) | 501(c)(3) | North Bethesda, MD | $39 million |
| American Academy of Orthopedic Surgeons (AAOS) | 501(c)(3) | Rosemont, IL | $39 million |
| American Academy of Dermatology | 501(c)(3) | Rosemont, IL | $38 million |
| Pennsylvania Horticultural Society (PHS) | 501(c)(3) | Philadelphia, PA | $37 million |
| National Council of Architectural Registration Boards (NCARB) | 501(c)(6) | Washington, DC | $36 million |
| American College of Rheumatology | 501(c)(6) | Atlanta, GA | $36 million |
| The American Institute of Architects (AIA) | 501(c)(6) | Washington, DC | $35 million |
| Association of The United States Army | 501(c)(3) | Arlington, VA | $35 million |
| American Urological Association Education and Research | 501(c)(3) | Linthicum HTS, MD | $35 million |
| Infectious Diseases Society of America (IDSA) | 501(c)(6) | Arlington, VA | $34 million |
| Society of Critical Care Medicine | 501(c)(3) | MT Prospect, IL | $32 million |
| American Osteopathic Association (AOA) | 501(c)(3) | Chicago, IL | $32 million |
| Water For People | 501(c)(3) | Greenwood Village, CO | $32 million |
| American Gastroenterological Association Institute | 501(c)(3) | Bethesda, MD | $32 million |
| Institute of Food Technologists (IFT) | 501(c)(3) | Chicago, IL | $31 million |
| Association of Zoos and Aquariums | 501(c)(3) | Silver Spring, MD | $31 million |
| American Society of Nephrology (ASN) | 501(c)(3) | Washington, DC | $31 million |
| Council of Chief State School Officers | 501(c)(3) | Washington, DC | $30 million |
| American Society for Engineering Education | 501(c)(3) | Washington, DC | $30 million |
| American Association of Nurse Anesthetists | 501(c)(6) | Rosemont, IL | $30 million |
| Oncology Nursing Society | 501(c)(6) | Pittsburgh, PA | $29 million |
| American Association for Justice (AAJ) | 501(c)(6) | Washington, DC | $29 million |
| Endocrine Society | 501(c)(3) | Washington, DC | $28 million |
| American Association of Nurse Practitioners | 501(c)(6) | Austin, TX | $28 million |
| American Public Works Association | 501(c)(3) | Kansas City, MO | $27 million |
| International Citycounty Management Association | 501(c)(3) | Washington, DC | $27 million |
| American College of Cardiology (ACC) | 501(c)(6) | Washington DC, DC | $27 million |
| Water Environment Federation (WEF) | 501(c)(3) | Alexandria, VA | $26 million |
| American Society of Radiologic Technologists (ASRT) | 501(c)(6) | Albuquerque, NM | $26 million |
| American Retirement Association (ASPPA) | 501(c)(6) | Arlington, VA | $26 million |
| Texas Medical Association (TMA) | 501(c)(6) | Austin, TX | $26 million |
| American Association of Orthodontists | 501(c)(6) | Saint Louis, MO | $25 million |
| American Association of Orthopaedic Surgeons (AAOS) | 501(c)(6) | Rosemont, IL | $25 million |
| Catholic Health Association of the United States | 501(c)(3) | Saint Louis, MO | $24 million |
| International Masonry Training and Education Foundation (IMTEF) | 501(c)(3) | Bowie, MD | $24 million |
| American Society for Radiation Oncology (ASTRO) | 501(c)(6) | Arlington, VA | $24 million |
| Council of Insurance Agents and Brokers | 501(c)(6) | Washington, DC | $23 million |
| Educause | 501(c)(3) | Boulder, CO | $23 million |
| American Society for Quality | 501(c)(3) | Milwaukee, WI | $23 million |
| ASIS International | 501(c)(6) | Alexandria, VA | $23 million |
| American Society of Association Executives | 501(c)(6) | Washington, DC | $22 million |
| LeadingAge WA | 501(c)(3) | Washington, DC | $22 million |
| National Association of Secondary -school Principals (NASSP) | 501(c)(3) | Reston, VA | $22 million |
| Association of Social Work Boards | 501(c)(3) | Culpeper, VA | $22 million |
| American Association for Clinical Chemistry (AACC) | 501(c)(3) | Washington, DC | $21 million |
| American Institute of Aeronautics and Astronautics / Headquarters Umbrella (AIAA) | 501(c)(3) | Reston, VA | $21 million |
| Inteleos (ARDMS) | 501(c)(6) | Rockville, MD | $20 million |
| Institute of Management Accountants | 501(c)(3) | Montvale, NJ | $20 million |
| National Association for the Education of Young Children | 501(c)(3) | Washington, DC | $20 million |
| International Society for Technology in Education | 501(c)(3) | Arlington, VA | $20 million |
| American Occupational Therapy Association (AOTA) | 501(c)(6) | North Bethesda, MD | $20 million |
| American Association of School Administrators (AASA) | 501(c)(3) | Alexandria, VA | $20 million |
| American Association of Colleges of Osteopathic Medicine (AACOM) | 501(c)(3) | Bethesda, MD | $19 million |
| Drug Information Association | 501(c)(3) | Washington, DC | $19 million |
| Physicians Committee for Responsible Medicine (PCRM) | 501(c)(3) | Washington, DC | $19 million |
| Heart Rhythm Society (HRS) | 501(c)(3) | Washington, DC | $19 million |
| American Immigration Lawyers Association (AILA) | 501(c)(6) | Washington, DC | $18 million |
| Association of Women's Health Obstetric and Neonatal Nurses (AWHONN) | 501(c)(3) | Washington, DC | $18 million |
| International Association of Fire Chiefs (IAFC) | 501(c)(3) | Mclean, VA | $17 million |
| American Physiological Society (APS) | 501(c)(3) | Rockville, MD | $17 million |
| Society of Women Engineers | 501(c)(3) | Chicago, IL | $17 million |
| American Industrial Hygiene Association (AIHA) | 501(c)(6) | Falls Church, VA | $17 million |
| American Meteorological Society | 501(c)(3) | Boston, MA | $17 million |
| Council for Professional Recognition | 501(c)(3) | Washington, DC | $16 million |
| American College of Radiology (ACR) | 501(c)(6) | Reston, VA | $16 million |
| Casualty Actuarial Society (CAS) | 501(c)(6) | Arlington, VA | $16 million |
| American Academy of Allergy, Asthma and Immunology (AAAAI) | 501(c)(3) | Milwaukee, WI | $15 million |
| Society of Nuclear Medicine and Molecular Imaging (SNMMI) | 501(c)(3) | Reston, VA | $15 million |
| Academy of General Dentistry (AGD) | 501(c)(6) | Chicago, IL | $15 million |
| Academy of Management (AOM) | 501(c)(3) | Briarcliff Manor, NY | $15 million |
| Risk and Insurance Management Society (RIMS) | 501(c)(6) | New York, NY | $15 million |
| Association for Professionals in Infection Control and Epidemiology | 501(c)(3) | Arlington, VA | $15 million |
| International Society of Automation (ISA) | 501(c)(3) | Research Triangle Park, NC | $14 million |
| American Counseling Association | 501(c)(3) | Alexandria, VA | $14 million |
| American Academy of Actuaries | 501(c)(6) | Washington, DC | $14 million |
| Physician Assistant Education Association | 501(c)(3) | Washington, DC | $14 million |
| Pharmacy Technician Certification Board (PTCB) | 501(c)(6) | Washington, DC | $14 million |
| Association of Community Cancer Centers (ACCC) | 501(c)(3) | Rockville, MD | $14 million |
| Accreditation Board for Engineering and Technology | 501(c)(3) | Baltimore, MD | $14 million |
| American Council on the Teaching of Foreign Languages | 501(c)(3) | Alexandria, VA | $14 million |
| Association of Diabetes Care and Education Specialists | 501(c)(6) | Chicago, IL | $13 million |
| Regulatory Affairs Professionals Society (RAPS) | 501(c)(3) | Rockville, MD | $13 million |
| Society of Interventional Radiology (SIR) | 501(c)(6) | Fairfax, VA | $13 million |
| American Society of Addiction Medicine / Colorado | 501(c)(3) | Rockville, MD | $12 million |
| American Educational Research Association | 501(c)(3) | Washington, DC | $12 million |
| American College of Healthcare Executives (ACHE) | 501(c)(6) | Chicago, IL | $12 million |
| American Academy of Child and Adolescent Psychiatry | 501(c)(3) | Washington, DC | $11 million |
| Public Relations Society of America / Group Central | 501(c)(6) | New York, NY | $11 million |
| American Society for Biochemistry and Molecular Biology | 501(c)(3) | Rockville, MD | $11 million |
| American Association of Physicists in Medicine (AAPM) | 501(c)(3) | Alexandria, VA | $11 million |
| International Association for the Study of Lung Cancer | 501(c)(3) | Denver, CO | $11 million |
| American School Counselor Association (ASCA) | 501(c)(3) | Alexandria, VA | $10 million |
| Association of Fundraising Professionals - National Headquarters (AFP) | 501(c)(6) | Arlington, VA | $10 million |
| American Association of Collegiate Registrars and Admissions Officers | 501(c)(3) | Washington, DC | $10 million |
| Association of Home Appliance Manufacturers (AHAM) | 501(c)(6) | Washington, DC | $10 million |
| The Association for Research in Vision and Ophthalmology | 501(c)(3) | Rockville, MD | $10 million |
| National League for Nursing | 501(c)(3) | Washington, DC | $9.7 million |
| American Health Lawyers Association (AHLA) | 501(c)(3) | Washington, DC | $9.5 million |
| The New York State Society of Certified Public Accountants | 501(c)(6) | New York, NY | $8.8 million |
| Arthroscopy Association of North America | 501(c)(3) | Rosemont, IL | $8.6 million |
| National Pharmaceutical Council (NPC) | 501(c)(6) | Washington, DC | $8.2 million |
| American Academy of Otolaryngology - Head and Neck Surgery (AAO-HNS) | 501(c)(6) | Alexandria, VA | $8.2 million |
| American Society of Interior Designers (ASID) | 501(c)(6) | Washington, DC | $7.7 million |
| American Society for Cell Biology (ASCB) | 501(c)(3) | Rockville, MD | $7.7 million |
| National Institute of Governmental Purchasing | 501(c)(3) | Herndon, VA | $7.6 million |
| The American Geriatrics Society | 501(c)(3) | New York, NY | $7.5 million |
| Asm International | 501(c)(3) | Materials Park, OH | $7.4 million |
| National Association of Elementary School Principals (NAESP) | 501(c)(6) | Alexandria, VA | $7.3 million |
| Public Affairs Council | 501(c)(4) | Washington, DC | $6.9 million |
| Council for Economic Education | 501(c)(3) | New York, NY | $6.6 million |