| 501 | 4389 | National Institute of Statistical Sciences |  | 3730 | 2538 | 2538 | 3879 |
| 502 | 7629 | New Jersey Equine Clinic | | 7740 | 7226 | 2538 | 3879 |
| 503 | 1493 | Northwestern Medicine (Northwestern Memorial Hospital) | | 573 | 370 | 442 | 3879 |
| 504 | 3838 | National Minority AIDS Council | | 3934 | 1697 | 2538 | 3879 |
| 505 | 7279 | US Naval Observatory Flagstaff Station | | 7570 | 6630 | 2538 | 3879 |
| 506 | 1536 | NORC University of Chicago | | 1581 | 290 | 1070 | 3879 |
| 507 | 7829 | Northern California Research Corporation | | 7553 | 7613 | 2538 | 3879 |
| 508 | 7265 | VA Northern Indiana Health Care System | | 6869 | 6706 | 2538 | 3879 |
| 509 | 6523 | Northwest Orthopaedic Institute | | 7255 | 5413 | 2538 | 3879 |
| 510 | 4275 | Norwalk Hospital | | 4350 | 2325 | 2538 | 3879 |
| 511 | 7133 | Norwood Clinic | | 7767 | 6303 | 2538 | 3879 |
| 512 | 7563 | Phoenix Heart Center | | 8091 | 6807 | 2538 | 3879 |
| 513 | 6023 | National Perinatal Information Center | | 6580 | 4721 | 2538 | 3879 |
| 514 | 1223 | National Radio Astronomy Observatory | | 243 | 153 | 510 | 3879 |
| 515 | 6304 | Olin Neuropsychiatry Research Center | | 7137 | 5079 | 2538 | 3879 |
| 516 | 3222 | National Research Council Canada |  | 4029 | 923 | 2538 | 3879 |
| 517 | 6960 | Northern Rockies Conservation Cooperative | | 8011 | 5721 | 2538 | 3879 |
| 518 | 4275 | National Research Corporation | | 4805 | 2291 | 2538 | 3879 |
| 519 | 3347 | USDA Forest Service Northern Research Station | | 505 | 1252 | 2538 | 3879 |
| 520 | 7292 | National Surgery Adjuvant Breast Bowel Project | | 6302 | 6813 | 2538 | 3879 |
| 521 | 2473 | Natural Sciences and Engineering Research Council of Canada | | 556 | 431 | 2538 | 3879 |
| 522 | 4149 | North-South Institute | | 4166 | 2109 | 2538 | 3879 |
| 523 | 3068 | National Tropical Botanical Garden | | 3600 | 786 | 2538 | 3879 |
| 524 | 3474 | National Telecommunications and Information Administration | | 735 | 1404 | 2538 | 3879 |
| 525 | 5031 | RIT National Technical Institute for the Deaf | | 2379 | 3612 | 2538 | 3879 |
| 526 | 2468 | National Technical Information Service | | 1267 | 386 | 2538 | 3879 |
| 527 | 6021 | USGS National Wildlife Health Center | | 6156 | 4769 | 2538 | 3879 |
| 528 | 4099 | Northwest Hospital & Medical Center | | 4022 | 2064 | 2538 | 3879 |
| 529 | 2406 | New York Blood Center | | 5460 | 1151 | 1249 | 3879 |
| 530 | 5182 | New York Headache Center | | 5025 | 3610 | 2538 | 3879 |
| 531 | 4734 | Oklahoma Blood Institute | | 6351 | 2880 | 2538 | 3879 |
| 532 | 3716 | Carnegie Observatories | | 2007 | 1623 | 2538 | 3879 |
| 533 | 7186 | Ocala Heart and Vascular Institute | | 7553 | 6471 | 2538 | 3879 |
| 534 | 5188 | Oceanic Institute | | 7271 | 3367 | 2538 | 3879 |
| 535 | 4142 | Oregon College of Oriental Medicine | | 4017 | 2300 | 2521 | 3879 |
| 536 | 7235 | Orlando Clinical Research Center | | 7368 | 6589 | 2538 | 3879 |
| 537 | 4937 | Ogden Clinic | | 5040 | 3284 | 2538 | 3879 |
| 538 | 6476 | Hipple Cancer Research Center | | 6230 | 5458 | 2538 | 3879 |
| 539 | 3110 | Oregon Institute of Science and Medicine | | 6107 | 741 | 2538 | 3879 |
| 540 | 6760 | VA Office of Information & Technology | | 633 | 6338 | 2538 | 3879 |
| 541 | 5111 | Omega-3 Research Institute | | 7945 | 2904 | 2538 | 3879 |
| 542 | 6643 | National Pediatric Myoclonus Center | | 7532 | 5567 | 2538 | 3879 |
| 543 | 6790 | Ontar Corporation | | 7725 | 5743 | 2538 | 3879 |
| 544 | 7624 | Ontario Hydro Energy | | 8091 | 6958 | 2538 | 3879 |
| 545 | 6095 | Outcomes Research Institute | | 4719 | 5011 | 2538 | 3879 |
| 546 | 4545 | Ontario Research Center for Computer Algebra | | 5048 | 2688 | 2538 | 3879 |
| 547 | 4351 | Oregon Clinic | | 4304 | 2446 | 2538 | 3879 |
| 548 | 6930 | Orentreich Foundation for Advancement of Science | | 6922 | 6151 | 2538 | 3879 |
| 549 | 7122 | Orthopaedic Research of Virginia | | 5884 | 6526 | 2538 | 3879 |
| 550 | 3295 | Ohio Supercomputer Center | | 2823 | 1052 | 2538 | 3879 |
| 551 | 2524 | OSF Saint Francis Medical Center | | 894 | 954 | 2258 | 3879 |
| 552 | 4319 | Osiris Therapeutics | | 3743 | 2436 | 2538 | 3879 |
| 553 | 5776 | Oklahoma State University Medical Center | | 6695 | 4355 | 2538 | 3879 |
| 554 | 3431 | Pacific Whale Foundation | | 4671 | 1152 | 2538 | 3879 |
| 555 | 2614 | Pacific Institute for Studies in Development Environment and Security | | 2749 | 458 | 2538 | 3879 |
| 556 | 3002 | David and Lucile Packard Foundation | | 2535 | 773 | 2538 | 3879 |
| 557 | 6227 | University of Washington College of Forest Resources | | 7396 | 4910 | 2538 | 3879 |
| 558 | 4042 | Pankey Institute | | 4658 | 1933 | 2538 | 3879 |
| 559 | 5598 | Parkinson's Institute | | 7634 | 3849 | 2538 | 3879 |
| 560 | 6825 | Trinity Regional Hospital Fort Dodge | | 7475 | 5883 | 2538 | 3879 |
| 561 | 2900 | PeaceHealth Southwest Medical Center (Southwest Washington Medical Center) | | 1077 | 745 | 2538 | 3879 |
| 562 | 5803 | Peachtree Orthopaedic Clinic | | 7041 | 4339 | 2538 | 3879 |
| 563 | 4478 | Pediatrix Medical Group | | 2679 | 2772 | 2538 | 3879 |
| 564 | 6412 | Paparella Ear Head and Neck Institute | | 6788 | 5304 | 2538 | 3879 |
| 565 | 7292 | Pelosi Medical Center | | 7468 | 6675 | 2538 | 3879 |
| 566 | 3046 | Property and Environment Research Center | | 3062 | 790 | 2538 | 3879 |
| 567 | 5620 | Partners HealthCare Personalized Medicine Genetics and Genomics | | 6722 | 4099 | 2538 | 3879 |
| 568 | 6447 | Postgraduate Center for Mental Health | | 7580 | 5230 | 2538 | 3879 |
| 569 | 3708 | DoD Food Analysis and Diagnostics | | 3653 | 1518 | 2538 | 3879 |
| 570 | 6572 | Pacific International Center for High Technology Research | | 6430 | 5601 | 2538 | 3879 |
| 571 | 1340 | Peterson Institute for International Economics | | 1182 | 196 | 524 | 3879 |
| 572 | 4704 | Pacific Institute for the Mathematical Sciences | | 1751 | 3198 | 2538 | 3879 |
| 573 | 4670 | Pinchot Institute for Conservation | | 4459 | 2946 | 2538 | 3879 |
| 574 | 7442 | Kushner Electroplating School | | 7775 | 6874 | 2538 | 3879 |
| 575 | 5399 | Pittsburgh Mercy Health System | | 7843 | 3471 | 2538 | 3879 |
| 576 | 1177 | Pacific Northwest National Laboratory | | 441 | 211 | 27 | 3879 |
| 577 | 4971 | Pacific Northwest Diabetes Research Institute | | 7012 | 4003 | 2445 | 3879 |
| 578 | 2669 | Point Blue (Point Reyes Bird Observatory) | | 3605 | 1544 | 1434 | 3879 |
| 579 | 2764 | National Capital Poison Center | | 5531 | 499 | 2538 | 3879 |
| 580 | 4384 | VA Polytrauma System of Care | | 7193 | 2205 | 2538 | 3879 |
| 581 | 7689 | VA Medical Center Poplar Bluff Missouri | | 7598 | 7385 | 2538 | 3879 |
| 582 | 6050 | Plano Orthopedic and Sports Medicine Center | | 5859 | 4843 | 2538 | 3879 |
| 583 | 3830 | Potomac Institute for Policy Studies | | 3185 | 1728 | 2538 | 3879 |
| 584 | 4161 | Powder Coating Institute | | 5175 | 2067 | 2538 | 3879 |
| 585 | 6346 | Premier Bone & Joint Centers (Gem City Bone and Joint Clinic) | | 5964 | 5281 | 2538 | 3879 |
| 586 | 6888 | Presbyterian Ear Institute | | 7617 | 5950 | 2538 | 3879 |
| 587 | 7386 | VA Health Care System Northern Arizona | | 7086 | 6885 | 2538 | 3879 |
| 588 | 7638 | VHA National Center for Health Promotion & Disease Prevention | | 5729 | 7403 | 2538 | 3879 |
| 589 | 7697 | Proteogenomics Research Institute for Systems Medicine | | 7904 | 7270 | 2538 | 3879 |
| 590 | 6981 | Prosthetics and Sensory Aids Service | | 7030 | 6230 | 2538 | 3879 |
| 591 | 1360 | Providence Saint John's Health Center | | 42 | 246 | 947 | 3879 |
| 592 | 6332 | Providence Medical Group (South Carolina Heart Center) | | 6832 | 5185 | 2538 | 3879 |
| 593 | 7076 | Prosthetics Research Study | | 7389 | 6307 | 2538 | 3879 |
| 594 | 2603 | Pittsburgh Supercomputing Center | | 2196 | 465 | 2538 | 3879 |
| 595 | 3774 | National Center for Posttraumatic Stress Disorder | | 3434 | 1626 | 2538 | 3879 |
| 596 | 5077 | Office of Public Health and Environmental Hazards | | 5431 | 3441 | 2538 | 3879 |
| 597 | 5497 | Patuxent Wildlife Research Center | | 3468 | 4214 | 2538 | 3879 |
| 598 | 4525 | Queen's Medical Center Honolulu Hawaii | | 6809 | 2486 | 2538 | 3879 |
| 599 | 7536 | Quality Enhancement Research Initiative | | 5460 | 7237 | 2538 | 3879 |
| 600 | 6197 | Radiology Associates of Tallahassee | | 7106 | 4931 | 2538 | 3879 |
