| CIC | Certified in Infection Control |
| CIRS | Certified Insurance Rehabilitation Specialist |
| CLCP | Certified Life Care Planner |
| CLLF | Cammy Lee Leukemia Foundation |
| CLNC | Certified Legal Nurse Consultant |
| CML | Chronic Myelogenous Leukemia |
| CMT | Certified Medical Transcriptionist |
| CN | Clinical Nurse (Australia = level 2) |
| CNA | Certified Nurses Aid ; Certified Nursing Administration |
| CNAA | Certified Nursing Administration, Advanced |
| CNC | Clinical Nurse Consultant (Australia = level 3) |
| CNCC(C) | Certified Nurse, Critical Care (Canada) |
| CNeph(C) | Certified Nurse, Critical Care, Nephrology (Canada) |
| CNSD | Certified Nutrition Support Dietitian USA |
| CNS | Clinical Nurse Specialist |
| CNM | Certified Nurse Midwife |
| CNN | Certified Nephrology Nurse |
| CNN(C) | Certified Nurse, Critical Care, Neuroscience (Canada) |
| CNO | Chief Nursing Officer |
| CNOR | Certified Nurse Operating Room (USA) |
| CNRN | Certified Neuroscience Registered Nurse |
| CO | Certified Orthoptrist (works with people with strabismus) |
| COA | Certified Ophthalmic Assistant |
| COHN | Certified Occupational Health Nurse |
| COHN(C) | Certified Nurse, Critical Care, Occupational Health (Canada) |
| COHN-S | Certified Occupational Health Nurse Specialist |
| COHC | Certified Occupational Hearing Conservationist |
| COMT | Certified Ophthalmic Medical Technologist |
| CON(C) | Certified Nurse, Critical Care, Oncology (Canada) |
| COP | Center of Pressure; Colloid Osmotic Pressure |
| Community Outreach Program |
| CPMHN(C) | Certified Psychiatric Mental Health Nurse (Canada) |
| COPS | Conditions of Participation (guidelines for home care agencies for Medicare Program) |
| COT | Certified Ophthalmic Technician |
| COTA | Certified Occupational Therapy Assistant |
| CPAN | Certiried Peri Anesthesia Nurse (Part of the organizations of ASPAN) |
| CPFT | Certified Pulmonary Function Technician |
| CPHQ | Certified Professional in Healthcare Quality |
| CPN (C) | Certified Rerioperative Nurse (Canada-is analogous to the CNOR in the USA) |
| Certified Pediatric Nurse |
| CPNP | Certified Pediatric Nurse Practitioner. |
| CPON | Certified Pediatric Oncology Nurse |
| CPP | Certified Pain Practitioner (American Academy of Pain Management) |
| CPR | Cardiopulmonary Resuscitation |
| CPT | Community Practice Teacher U.K. |
| CPTC | Certified Procurement Transplant Coordinator |
| CRC | Certified Rehabilitation Counselor |
| CRA | Certified Retinal Angiogrpher |
| CRANA | Council of Remote Area Nurses of Australia |
| CRN | Certified Radiology Nurse (American Association of Radiology Nurses) |
| CRNA | Certified Registered Nurse Anesthetist |
| CRNFA | Certified Registered Nurse First Assistant |
| CRNH | Certified Registered Nurse Hospice |
| CRNI | Certified Registered Nurse of Infusion |
| Certified Registered Nurse, Intravenous |
| CRNO | Certified Registered Nurse in Ophthalmology |
| CRNP | Certified Registered Nurse Practitioner |
| CRRN | Certified Rehabilitation Registered Nurse |
| CRTT | Certified Respiratory Therapy Technician |
| CS | Clinical Specialist CS; Certified Specialist |
| CSA | Certified Surgical Assistant (National Surgical Assistant Association) |
| CSN | Certified School Nurse |
| CST | Certified Surgical Technologist |
| CTBS | Certified Tissue Banking Specialist |
| CTN | Certified Transplant Nurse; Certified Transcultural Nurse |
| CTU | Contraceptive Technology Update |
| CUNP | Certified Urologic Nurse Practitioner |
| CUPA | Certified Urologic Physician Assistant |
| CURN | Certified Urologic Registered Nurse |
| CV | Career Vitae or Curriculum Vitae |
| CVICU | Cardiovascular Intensive Care Unit |
| CVVH | Continuous Veno-Venous Hemofiltration |
| CVVHD | Continuous Veno-Veno Hemodialysis |
| CWCN | Certified Wound Care Nurse |
| CWOCN | Certified Wound, Ostomy, and Continence Nurse |
| DISH | Diffuse Idiopathic Skeletal Hyperostosis (Forrestier's Syndrome) |
| DNSc | Doctor of Nursing Science |
| DO | Doctor of Osteopathy |
| Doctor of Ophthalmology |
| Diploma in Optometry |
| Diploma in Ophthalmology (UK) |
| DON | Director of Nursing (Australia = level 5) |
| DSN | Doctor of Science in Nursing |
| DTR | Dietetic Technician Registered |
| ED | Emergency Department |
| EdD | Doctorate of Education |
| EDF | Emergency Department Physician |
| EMT-1 | Emergency Medical Technician 1 (Basic) |
| EMT-P | Emergency Medical Technician-Paramedic |
| EN | Enrolled Nurse (Australia) |
