Nearly 10% of ACS Fellows are International Fellows. Approximately 140 nations in addition to the U.S. and Canada are represented in our membership.
| Country | Fellow | Associate | Resident | Medical Student | Affiliate | Total |
| Afghanistan | 1 | 1 | 1 | 3 | ||
| Albania | 2 | 2 | ||||
| Algeria | 2 | 2 | ||||
| Andorra | 1 | 1 | ||||
| Anguilla | 1 | 1 | ||||
| Antigua And Barbuda | 3 | 1 | 1 | 5 | ||
| Argentina | 242 | 15 | 1 | 2 | 260 | |
| Aruba | 1 | 1 | 2 | |||
| Australia | 220 | 12 | 3 | 2 | 2 | 239 |
| Austria | 32 | 2 | 1 | 35 | ||
| Azerbaijan | 1 | 1 | ||||
| Bahamas | 9 | 1 | 10 | |||
| Bahrain | 5 | 2 | 2 | 9 | ||
| Bangladesh | 25 | 2 | 27 | |||
| Barbados | 3 | 3 | ||||
| Belarus | 1 | 1 | ||||
| Belgium | 40 | 1 | 41 | |||
| Belize | 2 | 2 | ||||
| Bermuda | 3 | 3 | ||||
| Bolivia | 29 | 2 | 31 | |||
| Botswana | 1 | 1 | ||||
| Brazil | 286 | 28 | 14 | 13 | 341 | |
| Brunei Darussalam | 1 | 1 | 2 | |||
| Bulgaria | 4 | 1 | 5 | |||
| Cameroon | 2 | 1 | 3 | |||
| Canada | 1329 | 106 | 367 | 27 | 12 | 1841 |
| Cayman Islands | 2 | 2 | ||||
| Chile | 172 | 9 | 1 | 1 | 183 | |
| China | 174 | 17 | 2 | 4 | 197 | |
| Colombia | 107 | 20 | 14 | 2 | 143 | |
| Costa Rica | 27 | 3 | 30 | |||
| Croatia | 1 | 2 | 3 | |||
| Cuba | 1 | 1 | ||||
| Curaçao | 2 | 1 | 3 | |||
| Cyprus | 13 | 2 | 1 | 16 | ||
| Czech Republic | 2 | 2 | ||||
| Denmark | 7 | 1 | 4 | 5 | 17 | |
| Dominican Republic | 35 | 11 | 46 | |||
| Ecuador | 76 | 23 | 2 | 1 | 102 | |
| Egypt | 69 | 13 | 2 | 84 | ||
| El Salvador | 8 | 5 | 13 | |||
| Estonia | 3 | 1 | 4 | |||
| Ethiopia | 1 | 1 | ||||
| Fiji | 1 | 1 | ||||
| Finland | 2 | 2 | ||||
| France | 53 | 4 | 57 | |||
| Georgia | 3 | 3 | 6 | |||
| Germany | 149 | 12 | 7 | 168 | ||
| Ghana | 2 | 1 | 3 | 6 | ||
| Greece | 166 | 14 | 5 | 3 | 2 | 190 |
| Guatemala | 9 | 2 | 1 | 12 | ||
| Haiti | 4 | 2 | 2 | 1 | 9 | |
| Honduras | 6 | 2 | 8 | |||
| Hong Kong | 4 | 1 | 5 | |||
| Hungary | 7 | 7 | ||||
| Iceland | 6 | 6 | ||||
| India | 402 | 86 | 6 | 2 | 1 | 497 |
| Indonesia | 5 | 5 | ||||
| Iran, Islamic Republic Of | 39 | 1 | 40 | |||
| Iraq | 93 | 27 | 1 | 1 | 122 | |
| Ireland | 45 | 4 | 1 | 1 | 51 | |
| Israel | 87 | 3 | 90 | |||
| Italy | 158 | 20 | 18 | 5 | 201 | |
| Jamaica | 55 | 5 | 2 | 62 | ||
| Japan | 388 | 37 | 1 | 426 | ||
| Jordan | 75 | 22 | 11 | 108 | ||
| Kenya | 12 | 2 | 14 | |||
| Korea, Republic Of | 106 | 15 | 121 | |||
| Kuwait | 39 | 5 | 1 | 45 | ||
| Lebanon | 123 | 17 | 23 | 163 | ||
| Liberia | 1 | 1 | 2 | |||
| Libyan Arab Jamahiriya | 1 | 1 | ||||
| Macedonia, Republic of | 1 | 1 | 2 | |||
| Madagascar | 1 | 1 | ||||
| Malawi | 2 | 2 | ||||
| Malaysia | 36 | 4 | 40 | |||
| Malta | 2 | 1 | 3 | |||
| Man, Isle of | 1 | 1 | ||||
| Mauritius | 2 | 2 | ||||
| Mexico | 544 | 71 | 86 | 20 | 721 | |
| Monaco | 1 | 1 | ||||
| Mozambique | 2 | 2 | ||||
| Myanmar | 31 | 6 | 37 | |||
| Nepal | 4 | 1 | 5 | |||
| Netherlands | 13 | 2 | 15 | |||
| New Zealand | 29 | 2 | 1 | 32 | ||
| Nicaragua | 1 | 1 | ||||
| Niger | 1 | 1 | 2 | |||
| Nigeria | 79 | 19 | 3 | 4 | 105 | |
| Norway | 6 | 6 | ||||
| Oman | 14 | 3 | 17 | |||
| Pakistan | 73 | 26 | 4 | 1 | 1 | 105 |
| Palestinian Territory, Occupied | 1 | 1 | ||||
| Panama | 49 | 9 | 13 | 6 | 77 | |
| Papua New Guinea | 1 | 1 | 2 | |||
| Paraguay | 4 | 2 | 6 | |||
| Peru | 106 | 5 | 1 | 3 | 115 | |
| Philippines | 368 | 25 | 11 | 404 | ||
| Poland | 3 | 1 | 2 | 1 | 7 | |
| Portugal | 34 | 6 | 3 | 10 | 53 | |
| Puerto Rico | 4 | 1 | 11 | 16 | ||
| Qatar | 31 | 11 | 4 | 46 | ||
| Romania | 5 | 3 | 8 | |||
| Russian Federation | 2 | 2 | ||||
| Saint Kitts And Nevis | 2 | 2 | ||||
| Saint Lucia | 1 | 1 | ||||
| Saint Vincent And The Grenadines | 2 | 2 | ||||
| Saudi Arabia | 172 | 31 | 8 | 4 | 215 | |
| Serbia | 8 | 8 | ||||
| Sierra Leone | 1 | 1 | ||||
| Singapore | 38 | 8 | 34 | 1 | 81 | |
| Slovenia | 1 | 1 | ||||
| South Africa | 31 | 5 | 36 | |||
| Spain | 73 | 13 | 7 | 93 | ||
| Sri Lanka | 7 | 7 | ||||
| Sudan | 4 | 4 | ||||
| Suriname | 1 | 1 | ||||
| Sweden | 10 | 2 | 1 | 13 | ||
| Switzerland | 49 | 4 | 1 | 54 | ||
| Syrian Arab Republic | 11 | 1 | 12 | |||
| Taiwan | 51 | 3 | 54 | |||
| Tanzania, United Republic Of | 4 | 4 | ||||
| Thailand | 82 | 3 | 85 | |||
| Togo | 1 | 1 | ||||
| Trinidad And Tobago | 18 | 4 | 3 | 1 | 26 | |
| Tunisia | 6 | 1 | 7 | |||
| Turkey | 89 | 27 | 1 | 117 | ||
| Uganda | 1 | 1 | ||||
| Ukraine | 1 | 1 | 2 | |||
| United Arab Emirates | 106 | 26 | 132 | |||
| United Kingdom | 132 | 14 | 3 | 2 | 151 | |
| United States | 57771 | 2937 | 7124 | 1890 | 449 | 70171 |
| Uruguay | 22 | 1 | 23 | |||
| Venezuela | 83 | 3 | 1 | 87 | ||
| Virgin Islands, British | 1 | 1 | 2 | |||
| Virgin Islands, U.S. | 1 | 1 | 2 | |||
| Wallis And Futuna | 1 | 1 | ||||
| Yemen | 1 | 1 | ||||
| Zambia | 5 | 5 | ||||
| Zimbabwe | 4 | 4 |