| International Academy | 1,370 | regular | high |
| International Academy of Denver at Harrington | 152 | regular | other |
| International Academy of Flint K12 | 939 | regular | other |
| International Academy of Macomb | 461 | regular | high |
| International Academy of Saginaw | 74 | regular | other |
| International Academy of Smyrna | 328 | regular | elementary |
| International Charter Academy of Georgia | 268 | regular | elementary |
| International Charter School | 108 | regular | elementary |
| International Charter School | 377 | regular | elementary |
| International Charter School of Atlanta | 846 | regular | elementary |
| International Commerce High School - Phoenix | 202 | alternative | high |
| International Commerce High School - Tempe | 290 | alternative | high |
| International Commerce High School MCG | 50 | regular | high |
| International Community Elementary | 301 | regular | elementary |
| INTERNATIONAL COMMUNITY HIGH SCHOOL | 345 | regular | high |
| International Community School | 501 | regular | elementary |
| International Community School | 421 | alternative | other |
| INTERNATIONAL H S | 213 | alternative | high |
| International High School | 650 | regular | high |
| International High School @ Langley Park | 368 | regular | high |
| International High school @ Largo | 354 | regular | high |
| INTERNATIONAL HIGH SCHOOL AT LAFAYETTE | 331 | regular | high |
| INTERNATIONAL HIGH SCHOOL AT LAGUARDIA COMMUNITY COLLEGE | 455 | regular | high |
| INTERNATIONAL HIGH SCHOOL AT PROSPECT HEIGHTS | 303 | regular | high |
| INTERNATIONAL HIGH SCHOOL AT UNION SQUARE | 348 | regular | high |
| INTERNATIONAL HIGH SCHOOL FOR HEALTH SCIENCES | 292 | regular | high |
| International High School of New Orleans | 380 | regular | high |
| INTERNATIONAL LEADERSHIP CHARTER HIGH SCHOOL | 408 | regular | high |
| International Polytechnic High | 458 | alternative | high |
| International Prep Academy | 681 | regular | elementary |
| INTERNATIONAL PREPARATORY SCHOOL (THE) | 640 | regular | high |
| International School | 275 | regular | other |
| INTERNATIONAL SCHOOL | 933 | regular | other |
| International School | 600 | alternative | other |
| International School At Dundee | 342 | regular | elementary |
| INTERNATIONAL SCHOOL FOR LIBERAL ARTS | 491 | regular | other |
| International School for Science and Culture | 97 | regular | elementary |
| INTERNATIONAL SCHOOL OF AMERICA | 493 | regular | high |
| International School of Beaverton | 870 | regular | other |
| INTERNATIONAL SCHOOL OF BROWARD | 70 | regular | other |
| International School of Louisiana | 1,074 | regular | elementary |
| International School of Monterey | 439 | regular | elementary |
| International Spanish Language Acad | 447 | regular | elementary |
| INTERNATIONAL STUDIES ACADEMY HIGH SCHOOL | 234 | regular | high |
| INTERNATIONAL STUDIES ACADEMY MIDDLE SCHOOL | 288 | regular | middle |
| INTERNATIONAL STUDIES CHARTER HIGH SCHOOL | 376 | regular | high |
| INTERNATIONAL STUDIES CHARTER MIDDLE SCHOOL | 320 | regular | middle |
| International Studies Elementary Charter School | 470 | regular | elementary |
| International Studies Lrng Center at Legacy High Sch Complex | 867 | regular | other |
| INTERNATIONAL STUDIES MAGNET | 636 | regular | elementary |