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 January 6, 2026, 13,921 current active ATS Members.
| 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) | 1191 | 1943 | 3134 | 1836 | 721 | 1298 | 41% |
| Behavioral Science & Health Services Research (BSHSR) | 416 | 713 | 1129 | 914 | 361 | 215 | 19% |
| Clinical Problems (CP) | 2217 | 2669 | 4886 | 3246 | 1378 | 1640 | 34% |
| Critical Care (CC) | 3321 | 2782 | 6103 | 4877 | 2761 | 1226 | 20% |
| Enviromental, Occupational and Population Health (EOPH) | 481 | 808 | 1289 | 882 | 337 | 407 | 32% |
| Nursing (NUR) | 114 | 50 | 164 | 140 | 100 | 24 | 15% |
| Pediatrics (PEDS) | 1168 | 439 | 1607 | 1240 | 913 | 367 | 23% |
| Pulmonary Circulation (PC) | 841 | 1380 | 2221 | 1703 | 650 | 518 | 23% |
| Pulmonary Infections and Tuberculosis (Pi-TB) | 948 | 1901 | 2849 | 1584 | 442 | 1265 | 44% |
| Pulmonary Rehabilitation (PR) | 233 | 539 | 772 | 381 | 101 | 391 | 51% |
| Respiratory Cell and Molecular Biology (RCMB) | 906 | 1382 | 2288 | 1581 | 663 | 707 | 31% |
| Respiratory Structure and Function (RSF) | 766 | 1874 | 2640 | 1785 | 466 | 855 | 32% |
| Sleep and Respiratory Neurobiology (SRN) | 577 | 891 | 1468 | 874 | 359 | 594 | 40% |
| Thoracic Oncology | 742 | 792 | 1534 | 991 | 501 | 543 | 35% |
| Genetics & Genomics (GG) | 1121 | ||||||
| Medical Education (Med Ed) | 2878 | ||||||
| Terrorism & Inhalation Disasters (TID) | 399 | ||||||
| Members with NO Assembly Affiliation | |||||||