As a member of the American Thoracic Society you may join a maximum of three assemblies one “primary Assembly” and two “secondary Assembly's”. As of April 7, 2026, 14,480 have declared a primary Assembly.
| Assembly | Primary Members | Secondary Members | Primary & Secondary Members | Primary & Secondary (U.S. Only) | Primary (U.S. Only) | International Members | Percentage of International Members |
|---|---|---|---|---|---|---|---|
| Allergy, Immunology and Inflammation (AII) | 1224 | 1965 | 3189 | 1932 | 775 | 1257 | 39% |
| Behavioral Science & Health Services Research (BSHSR) | 443 | 747 | 1190 | 963 | 379 | 227 | 19% |
| Clinical Problems (CP) | 2303 | 2776 | 5079 | 3466 | 1485 | 1613 | 32% |
| Critical Care (CC) | 3555 | 2875 | 6430 | 5247 | 3024 | 1183 | 18% |
| Enviromental, Occupational and Population Health (EOPH) | 490 | 820 | 1310 | 918 | 358 | 392 | 30% |
| Nursing (NUR) | 111 | 56 | 167 | 143 | 99 | 24 | 14% |
| Pediatrics (PEDS) | 1252 | 453 | 1705 | 1312 | 981 | 393 | 23% |
| Pulmonary Circulation (PC) | 841 | 1380 | 2221 | 1703 | 650 | 518 | 23% |
| Pulmonary Infections and Tuberculosis (Pi-TB) | 943 | 1971 | 2914 | 1683 | 447 | 1231 | 42% |
| Pulmonary Rehabilitation (PR) | 242 | 557 | 799 | 399 | 109 | 400 | 50% |
| Respiratory Cell and Molecular Biology (RCMB) | 935 | 1339 | 2274 | 1630 | 699 | 644 | 28% |
| Respiratory Structure and Function (RSF) | 756 | 1936 | 2692 | 1881 | 466 | 811 | 30% |
| Sleep and Respiratory Neurobiology (SRN) | 610 | 924 | 1534 | 931 | 375 | 603 | 39% |
| Thoracic Oncology | 764 | 837 | 1601 | 1074 | 537 | 527 | 33% |
| Genetics & Genomics (GG) | 1099 | ||||||
| Medical Education (Med Ed) | 2826 | ||||||
| Terrorism & Inhalation Disasters (TID) | 375 | ||||||
| Members with NO Assembly Affiliation | |||||||