Medical Organizations
- Healthcare Financial Management Association (HFMA)
- Health Professionals Advancing LGBTQ Equality (GLMA)
- Healthy Aging Dietetic Practice Group (HADPG)
- Hearing & Balance Academy (HBA)
- Hearing Loss Association of America (HLAA)
- Heart Rhythm Society (HRS)
- Hermann-Oberth-Gesellschaft; Hermann Oberth Society (Germany) (HOG)
- Hillsborough County Medical Association (HCMA)
- Hispanic Dental Association (HDA)
- Holistic Dental Association (HDA)
- Homeopathic Academy of Naturopathic Physicians (HANP)
- Hospice and Palliative Nurses Association (HPNA)
- Hospital Consultants and Specialists Association (HCSA)
- Houston Area Lactation Consultants and Educators Association (HALCEA)
- Houston Area Nurse Practitioners (HANP)
- Houston Association for Marriage and Family Therapy (HAMFT)
- Houston Community for Emotionally Focused Therapy (HCEFT)
- Houston Counseling Association (HCA)
- Houston Group Psychotherapy Society (HGPS)
- Houston Society of Plastic Surgeons (HSPS)
- Hunger and Environmental Nutrition Dietetics Practice Group (HEN)
- Idaho Association of Community Providers (IACP)
- Idaho Association of Marriage and Family Counselors (IDAMFC)
- Idaho Parents Unlimited (IPUL)
- Idaho Psychological Association (IPA)
- Idaho State Board of Medicine (IBOM)
- Ida Institute (II)
- Illinois Academy of Family Physicians (IAFP)
- Illinois Art Therapy Association (IATA)
- Illinois Association for Behavioral Health (ILABH)
- Illinois Association for Multicultural Counseling (IAMC)
- Illinois Chiropractic Society (ICS)
- Illinois Coalition Against Domestic Violence (ICADV)
- Illinois Counseling Association (ICA)
- Illinois Heart & Lung Foundation (IHLF)
- Illinois Mental Health Counselors Association (IMHCA)
- Illinois Optometric Association (IOA)
- Illinois Podiatric Medical Association (IPMA)
- Illinois Society of Acupuncturists (ILSA)
- Illinois Speech-Language-Hearing Association (ISHA)
- Illinois State Medical Society (ISMS)
- Illinois Surgical Society (ISS)
- Indiana Counselor's Association on Alcohol and Drug Abuse (ICAADA)
- Indiana Dental Association (IDA)
- Indian Orthodontic Society (IOS)
- Industrial Accident Board (IAB)
- Infant Development Association (IDA)
- Infectious Diseases Society of America (IDSA)
- Infusion Nurses Society (INS)
- Institute for Biomedical Studies (IBS)
- Institute for Child Care Training Program (ICCTP)
- Institute for Clinical Research Education (ICRE)
- Institute for Clinical Systems Improvement (ICSI)
- Institute for Functional Medicine (IFM)
- Institute for Health Metrics and Evaluation (IMHE)
- Institute for Medical Information Processing, Statistics and Biomathematics (Germany) (ISB)
- Institute for Mental Diseases (IMD)
- Institute for Muscle Diseases (IMD)
- Institute for Nursing Research and Scholarship (INRS)
- Institute for Safe Medication Practices (ISMP)
- Institute of Allied Medical Professions (IAMP)
- Institute of Child Development (ICD)
- Institute of Contemporary Psychotherapy+Psychoanalysis (ICP+P)
- Institute of Educational Research (IER)
- Institute of Laser Technology in Medicine (ILM)
- Institute of Medical and Biological Illustrators (IMBI)
- Institute of Medical Laboratory Technology (UK) (IMLT)
- Institute of Medical Psychology (UK) (IMP)
- Institute of Medicine (IOM)
- Institute of Microbiology (IMB)
- Institute of Physical Medicine and Rehabilitation (IPMR)
- Institute of Plasma Physics (IPP)
- Institute of Rehabilitation Medicine (IRM)
- Institut für Angewandte Sozialwissenschaften; Institute for Applied Social Sciences (Germany) (INFAS)
- Institut für Medizinische Statistik; Institute of Medical Statistics (IMS)
- Institut für sozialmedizinische Präventions und Rehabilitationsforschung; Institute of Socio-Medical Prevention and Rehabilitation Research (IPR)
- Institut für Standardisierung und Dokumentation im medizinischen Laboratorium; Institute of Standardization and Documentation in the Medical Laboratory (INSTAND)
- Institut National de la Santé et de la Recherche Médicale; French National Institute of Health and Medical Research (INSERM)
- Inter-American Hospital Association (IAHA)
- Interdisciplinary Nursing Quality Research Initiative (INQRI)
- Interkantonale Kontrollstelle für Heilmittel; Intercantonal Supervision Agency for Drugs (Switzerland) (IKS)
- Internal Family Systems (IFS)
- International Academy of Behavioral Medicine, Counseling, and Psychotherapy (IABMCP)
- International Academy of Biological Dentistry & Medicine (IABDM)
- International Academy of Cytology (IAC)
- International Academy of Medical Acupuncture (IAMA)
- International Academy of Neuromuscular Therapy (IANMT)
- International Academy of Oral Medicine & Toxicology (IAOMT)
- International Academy of Osteopathy (IAO)
- International Academy of Pathology (IAP)
- International Advisory Committee on Biological Control (IACBC)
- International Affiliation of Tongue Tie Professionals (IATP)
- International Agency for Research on Cancer (IARC)
- International & American Associations Of Clinical Nutritionists (IAACN)
- International Anaplastology Association (IAA)
- International Anatomical Nomenclature (IAN)
- International Anatomical Nomenclature Committee (IANG)
- International Anesthesia Research Society (IARS)
- International Angstrom Unit (IA)
- International Association for Accident and Traffic Medicine (IAATM)