Hospital markets in most states became more concentrated between 2000 and 2026, according to state fact sheets released in October by Yale University’s Healthcare Affordability Lab.
The analysis covers general short-term acute care hospitals in each state and Washington, D.C. Each hospital’s market is defined as a 30-minute travel radius, and concentration is measured using the Herfindahl-Hirschman Index, which ranges from near 0 in highly competitive markets to 10,000 for a monopoly. Federal antitrust regulators consider markets above 1,800 “highly concentrated.” The lab notes that its measure is an analytical proxy, not a legally defined antitrust market, and that figures for 2024 to 2026 are preliminary.
Average market HHI climbed in more than 40 states and D.C. and fell in seven: Arizona, Colorado, Nebraska, Nevada, New Mexico, Utah and Wyoming. Pennsylvania had the largest increase, 1,771 points, followed by Delaware and Connecticut. Texas recorded the most ownership transactions since 2000, with 114, followed by Pennsylvania with 103.
Here is how each state’s hospital markets changed:
| State | Hospitals (2026) | Avg. HHI, 2000 | Avg. HHI, 2026 | Change | Transactions since 2000 |
| Alabama | 88 | 5,495 | 6,602 | +1,107 | 42 |
| Alaska | 21 | 8,778 | 9,168 | +390 | 4 |
| Arizona | 78 | 5,543 | 5,527 | -16 | 21 |
| Arkansas | 69 | 5,965 | 6,802 | +837 | 38 |
| California | 342 | 3,241 | 3,476 | +235 | 72 |
| Colorado | 85 | 6,409 | 6,354 | -55 | 17 |
| Connecticut | 32 | 3,168 | 4,834 | +1,666 | 25 |
| Delaware | 7 | 5,100 | 6,803 | +1,703 | 1 |
| District of Columbia | 5 | 1,351 | 1,750 | +399 | 1 |
| Florida | 216 | 4,234 | 4,324 | +90 | 57 |
| Georgia | 128 | 4,774 | 5,898 | +1,124 | 62 |
| Hawaii | 21 | 5,804 | 6,752 | +948 | 2 |
| Idaho | 41 | 7,164 | 7,319 | +155 | 12 |
| Illinois | 178 | 3,412 | 4,199 | +787 | 69 |
| Indiana | 114 | 4,504 | 4,882 | +378 | 33 |
| Iowa | 118 | 5,439 | 5,942 | +503 | 28 |
| Kansas | 122 | 5,393 | 5,401 | +8 | 25 |
| Kentucky | 96 | 4,678 | 5,964 | +1,286 | 34 |
| Louisiana | 111 | 3,620 | 4,785 | +1,165 | 36 |
| Maine | 37 | 7,316 | 8,297 | +981 | 11 |
| Maryland | 43 | 4,428 | 4,595 | +167 | 20 |
| Massachusetts | 71 | 3,679 | 4,503 | +824 | 30 |
| Michigan | 133 | 4,635 | 5,645 | +1,010 | 67 |
| Minnesota | 127 | 5,320 | 5,750 | +430 | 36 |
| Mississippi | 86 | 4,505 | 5,381 | +876 | 33 |
| Missouri | 103 | 4,865 | 5,275 | +410 | 34 |
| Montana | 62 | 8,525 | 8,687 | +162 | 8 |
| Nebraska | 87 | 5,490 | 5,453 | -37 | 11 |
| Nevada | 35 | 6,566 | 5,706 | -860 | 8 |
| New Hampshire | 27 | 5,109 | 5,981 | +872 | 7 |
| New Jersey | 69 | 1,970 | 3,197 | +1,227 | 38 |
| New Mexico | 46 | 7,368 | 7,053 | -315 | 11 |
| New York | 182 | 3,398 | 4,426 | +1,028 | 67 |
| North Carolina | 118 | 5,453 | 6,273 | +820 | 54 |
| North Dakota | 48 | 8,617 | 8,921 | +304 | 12 |
| Ohio | 158 | 3,877 | 4,792 | +915 | 59 |
| Oklahoma | 108 | 5,408 | 5,767 | +359 | 34 |
| Oregon | 59 | 6,617 | 6,766 | +149 | 17 |
| Pennsylvania | 173 | 3,587 | 5,358 | +1,771 | 103 |
| Rhode Island | 12 | 2,247 | 2,810 | +563 | 6 |
| South Carolina | 61 | 5,702 | 6,472 | +770 | 24 |
| South Dakota | 52 | 7,943 | 8,740 | +797 | 9 |
| Tennessee | 114 | 4,709 | 6,047 | +1,338 | 50 |
| Texas | 406 | 4,446 | 4,764 | +318 | 114 |
| Utah | 47 | 7,112 | 6,573 | -539 | 3 |
| Vermont | 15 | 7,404 | 7,536 | +132 | 2 |
| Virginia | 86 | 5,793 | 6,392 | +599 | 37 |
| Washington | 92 | 5,780 | 6,344 | +564 | 32 |
| West Virginia | 48 | 6,398 | 7,732 | +1,334 | 41 |
| Wisconsin | 131 | 4,931 | 5,201 | +270 | 33 |
| Wyoming | 29 | 9,384 | 9,172 | -212 | 1 |
