Links to: AB-AG AG-AL, AL-AN, AP-AS, AS-AX
| 653111 | APARTMENT FINDING & RENTAL SERVICE | 2922 | 3505 | |
| 571208 | APARTMENT FURNISHINGS | 63 | 76 | |
| 502301 | APARTMENT HOUSE SUPPLIES (WHOLESALE) | 26 | 31 | |
| 651304 | APARTMENT RENTAL AGENCIES | 67 | 80 | |
| 653110 | APARTMENT SHARING SERVICE | 65 | 78 | |
| 651303 | APARTMENTS | 87603 | 105124 | |
| 2389 | APPAREL & ACCESSORIES NEC | 779 | 935 | |
| 238998 | APPAREL & ACCESSORIES NEC (MFRS) | 711 | 853 | |
| 56 | APPAREL & ACCESSORY STORES | 200755 | 240906 | |
| 569947 | APPAREL & GARMENTS-RETAIL | 1014 | 1217 | |
| 23 | APPAREL & OTHER FINISHED PRODUCTS-MFRS | 28436 | 34123 | |
| 2387 | APPAREL-BELTS | 228 | 274 | |
| 238798 | APPAREL-BELTS (MANUFACTURERS) | 102 | 122 | |
| 513799 | APPAREL-CHLDRN/TEEN HEADWEAR WHOL/MFRS | 4 | 5 | |
| 513603 | APPAREL-MENS-WHOLESALE | 1822 | 2186 | |
| 513724 | APPAREL-WOMENS MILLINERY-JOBBERS | 2 | 2 | |
| D | APPEALS | 2120 | 2544 | |
| 581217 | APPETIZERS & SNACKS ETC | 52 | 62 | |
| 0 | APPLE | 1379 | 1655 | |
| 514811 | APPLE BROKERS | 2 | 2 | |
| 017504 | APPLE GROWERS | 8 | 10 | |
| 072315 | APPLE PACKERS | 3 | 4 | |
| 017505 | APPLE PRODUCTS | 8 | 10 | |
| 514813 | APPLE SHIPPERS | 1 | 1 | |
| 9 | APPLEBEE'S NEIGHBORHOOD GRILL | 533 | 640 | |
| 572202 | APPLIANCES-HOUSEHOLD-MAJOR-DEALERS | 20800 | 24960 | |
| 363901 | APPLIANCES-HOUSEHOLD-MAJOR-MANUFACTURERS | 104 | 125 | |
| 735941 | APPLIANCES-HOUSEHOLD-MAJOR-RENTING | 5194 | 6233 | |
| 762902 | APPLIANCES-HOUSEHOLD-MAJOR-REPAIRING | 14995 | 17994 | |
| 506401 | APPLIANCES-HOUSEHOLD-MAJOR-SUPLS (WHOL) | 2458 | 2950 | |
| 593208 | APPLIANCES-HOUSEHOLD-MAJOR-USED | 2638 | 3166 | |
| 506404 | APPLIANCES-HOUSEHOLD-MAJOR-WHOLESALE | 652 | 782 | |
| 769973 | APPLIANCES-HOUSEHOLD-REFINISHING | 270 | 324 | |
| 572207 | APPLIANCES-HOUSEHOLD-SMALL-DEALERS | 621 | 745 | |
| 762901 | APPLIANCES-HOUSEHOLD-SMALL-REPAIRING | 1248 | 1498 | |
| 593237 | APPLIANCES-HOUSEHOLD-SMALL-USED | 33 | 40 | |
| 506403 | APPLIANCES-HOUSEHOLD-SMALL-WHOLESALE | 104 | 125 | |
| 506518 | APPLIANCES-HSHLD-SMALL-SUPLS/PRTS (WHOL) | 275 | 330 | |
| 249912 | APPLICATORS (MANUFACTURERS) | 3 | 4 | |
| 738913 | APPRAISERS | 16922 | 20306 | |
| 653109 | APPRAISERS-INDUSTRIAL & COMMERCIAL | 31 | 37 | |
| 833103 | APPRENTICESHIP TRAINING PROGRAMS | 242 | 290 | |
| 569925 | APRONS-DOMESTIC & FANCY | 35 | 42 | |
| 513725 | APRONS-DOMESTIC & FANCY-WHOLESALE & MFRS | 12 | 14 | |
| 721802 | APRONS-INDUSTRIAL | 74 | 89 | |
| 232601 | APRONS-INDUSTRIAL-MANUFACTURERS | 14 | 17 | |
| 513128 | APRONS-INDUSTRIAL-WHOLESALE | 3 | 4 | |
| 027301 | AQUACULTURE | 84 | 101 | |
| 874858 | AQUACULTURE CONSULTANTS | 24 | 29 | |
| 599970 | AQUARIUMS & AQUARIUM SUPLS | 1969 | 2363 | |
| 799976 | AQUARIUMS & AQUARIUM SUPLS-LEASING/MNTC | 520 | 624 | |
| 323106 | AQUARIUMS & AQUARIUM SUPLS-MFRS | 52 | 62 | |
| 519916 | AQUARIUMS & AQUARIUM SUPLS-WHOLESALE | 118 | 142 | |
| 842205 | AQUARIUMS-PUBLIC | 48 | 58 | |
| 738907 | ARBITRATION SERVICES | 4601 | 5521 | |
| H | ARBOR DRUGS | 177 | 212 | |
| 8422 | ARBORETA & BOTANICAL GARDENS | 649 | 779 | |
| 842203 | ARBORETUMS | 44 | 53 | |
| 078304 | ARBORISTS | 72 | 86 | |
| N | ARBY'S | 2681 | 3217 | |
| 799303 | ARCADES | 187 | 224 | |
| 873301 | ARCHAEOLOGISTS | 315 | 378 | |
| 594143 | ARCHERY EQUIPMENT & SUPPLIES | 3020 | 3624 | |
| 394910 | ARCHERY EQUIPMENT & SUPPLIES-MFRS | 51 | 61 | |
| 509123 | ARCHERY EQUIPMENT & SUPPLIES-WHOLESALE | 32 | 38 | |
| 799902 | ARCHERY INSTRUCTION | 46 | 55 | |
| 799903 | ARCHERY RANGES | 476 | 571 | |
| 871202 | ARCHITECTS | 31989 | 38387 | |
| 871207 | ARCHITECTS & BUILDERS SERVICE | 306 | 367 | |
| 871205 | ARCHITECTS & ENGINEERS | 8 | 10 | |
| 874885 | ARCHITECTS SERVICE BUREAU | 4 | 5 | |
| 504901 | ARCHITECTS SUPPLIES (WHOLESALE) | 592 | 710 | |
| 395201 | ARCHITECTS SUPPLIES-MANUFACTURERS | 33 | 40 | |
| 871206 | ARCHITECTURAL & CONSTR SPECIFICATIONS | 244 | 293 | |
| 3446 | ARCHITECTURAL & ORNAMENTAL METAL WORK | 6286 | 7543 | |
| 874892 | ARCHITECTURAL CONSULTANTS | 10 | 12 | |
| 871217 | ARCHITECTURAL DESIGNERS | 37 | 44 | |
| 871204 | ARCHITECTURAL ILLUSTRATORS | 631 | 757 | |
| 871218 | ARCHITECTURAL MODELS | 37 | 44 | |
| 8712 | ARCHITECTURAL SERVICES | 39562 | 47474 | |
| 871298 | ARCHITECTURAL SERVICES | 102 | 122 | |
| 344698 | ARCHITECTURAL/ORNAMENTAL MTL WORK (MFRS) | 2323 | 2788 | |
| 841205 | ARCHIVES | 8 | 10 | |
| 2 | ARCO AIRE | 140 | 168 | |
| 2 | ARCO AIRE | 25 | 30 | |
| 2 | ARCO AIRE | 255 | 306 | |
| 2 | ARCO AIRE | 55 | 66 | |
| 2 | ARCO AIRE | 16 | 19 | |
| 516913 | ARGON (WHOLESALE) | 5 | 6 | |
| A | ARIENS | 1056 | 1267 | |
| 7694 | ARMATURE REWINDING SHOPS | 1928 | 2314 | |
| 506365 | ARMATURES (WHOLESALE) | 64 | 77 | |
| 769402 | ARMATURES-REPAIRING & REWINDING | 102 | 122 | |
| B | ARMCO BUILDING SYSTEMS | 11 | 13 | |
| A | ARMED FORCES | 218 | 262 | |
| 738103 | ARMORED CAR SERVICE | 624 | 749 | |
| 371106 | ARMORED CAR-MANUFACTURERS | 16 | 19 | |
| C | ARMSTRONG | 334 | 401 | |
| C | ARMSTRONG | 151 | 181 | |
| C | ARMSTRONG | 740 | 888 | |
| C | ARMSTRONG | 113 | 136 | |
| C | ARMSTRONG | 280 | 336 | |
| 0 | ARMSTRONG | 466 | 559 | |
| 561104 | ARMY & NAVY GOODS | 1191 | 1429 | |
| 231101 | ARMY & NAVY GOODS-MANUFACTURERS | 11 | 13 | |
| 513614 | ARMY & NAVY GOODS-WHOLESALE | 25 | 30 | |
| 723118 | AROMATHERAPY | 89 | 107 | |
| 4729 | ARRANGEMENT OF PASSENGER TRNSPRTN NEC | 15030 | 18036 | |
| 472999 | ARRANGEMENT OF PASSENGER TRNSPRTN NEC | 106 | 127 | |
| 4731 | ARRANGEMENT OF TRANSPORTATION-FREIGHT | 14182 | 17018 | |
| 841203 | ART CENTERS | 229 | 275 | |
| 599989 | ART CONSULTANTS | 27 | 32 | |
| 869915 | ART CULTURAL SOCIETIES | 14 | 17 | |
| 519918 | ART DEALERS-WHOLESALE | 293 | 352 | |
| 599969 | ART GALLERIES & DEALERS | 23230 | 27876 | |
| 519919 | ART GOODS-WHOLESALE | 157 | 188 | |
| 829919 | ART INSTRUCTION & SCHOOLS | 1956 | 2347 | |
| 503913 | ART METAL WORK (WHOLESALE) | 94 | 113 | |
| 274101 | ART PUBLISHERS | 94 | 113 | |
| 899908 | ART RESTORING | 1000 | 1200 | |
| 599968 | ARTIFICIAL BREASTS | 1494 | 1793 | |
| 508772 | ARTIFICIAL EYELASHES (WHOLESALE) | 4 | 5 | |
| 385107 | ARTIFICIAL EYES-HUMAN (MANUFACTURERS) | 246 | 295 | |
| 394203 | ARTIFICIAL EYES-TOYS & ANIMALS (MFRS) | 8 | 10 | |
| 723107 | ARTIFICIAL FINGERNAILS | 65 | 78 | |
| 599967 | ARTIFICIAL FLOWERS & PLANTS & TREES | 4031 | 4837 | |
| 399908 | ARTIFICIAL FLOWERS & PLANTS & TREES-MFRS | 97 | 116 | |
| 519311 | ARTIFICIAL FLOWERS/PLANTS-MFRS SUPL-WHOL | 21 | 25 | |
| 519303 | ARTIFICIAL FLOWERS-MTRLS/SUPLS (WHOL) | 18 | 22 | |
| 519302 | ARTIFICIAL FLOWERS-WHOLESALE | 220 | 264 | |
| 399902 | ARTIFICIAL FLWRS/PLANTS-MFRS SUPL (MFRS) | 67 | 80 | |
| 399962 | ARTIFICIAL FRUITS & FOOD (MANUFACTURERS) | 10 | 12 | |
| 179979 | ARTIFICIAL GRASS | 24 | 29 | |
| 809201 | ARTIFICIAL KIDNEY CENTERS | 35 | 42 | |
| 504715 | ARTIFICIAL LARYNXES (WHOLESALE) | 1 | 1 | |
| 599922 | ARTIFICIAL LIMBS | 2536 | 3043 | |
| 384203 | ARTIFICIAL LIMBS-MANUFACTURERS | 107 | 128 | |
| 399963 | ARTIFICIAL SNOW (MANUFACTURERS) | 2 | 2 | |
| 738914 | ARTISTS AGENTS | 328 | 394 | |
| 599965 | ARTISTS MATERIALS & SUPPLIES | 2117 | 2540 | |
| 395204 | ARTISTS MATERIALS-MANUFACTURERS | 29 | 35 | |
| 519921 | ARTISTS MATERIALS-WHOLESALE | 5 | 6 | |
| 733604 | ARTISTS-COMMERCIAL | 6208 | 7450 | |
| 899912 | ARTISTS-FINE ARTS | 4479 | 5375 | |
| 329906 | ARTS & CRAFTS SUPPLIES-MANUFACTURERS | 208 | 250 | |
| 799990 | ARTS & CRAFTS-INSTRUCTION | 39 | 47 | |
| 509210 | ARTS & CRAFTS-WHOLESALE | 41 | 49 | |
| 841202 | ARTS ORGANIZATIONS & INFORMATION | 2138 | 2566 | |
| 4 | ARVIN | 7 | 8 | |
| 503914 | ASBESTOS & ASBESTOS PRODUCTS (WHOLESALE) | 118 | 142 | |
| 329201 | ASBESTOS & ASBESTOS PRODUCTS-MFRS | 199 | 239 | |
| H | ASBESTOS INSPECTIONS & MGMT PLANNING | 108 | 130 | |
| 3292 | ASBESTOS PRODUCTS | 203 | 244 | |
| 179926 | ASBESTOS REMOVAL SERVICE | 2367 | 2840 | |
| 508477 | ASBESTOS REMOVAL SUPPLIES & EQUIP (WHOL) | 60 | 72 | |
| 326908 | ASBESTOS SUBSTITUTES (MANUFACTURERS) | 3 | 4 | |
| 829948 | ASBESTOS TRAINING SERVICE | 12 | 14 | |
| 873420 | ASBESTOS-CONSULTING & TESTING | 826 | 991 | |
| 866116 | ASHRAMS | 5 | 6 | |
| 161106 | ASPHALT & ASPHALT PRODUCTS | 7729 | 9275 | |
| 295101 | ASPHALT & ASPHALT PRODUCTS-MANUFACTURERS | 1460 | 1752 | |
| 503215 | ASPHALT AGGREGATES (WHOLESALE) | 11 | 13 | |
| 2952 | ASPHALT FELTS & COATINGS | 581 | 697 | |
| 295298 | ASPHALT FELTS & COATINGS (MFRS) | 329 | 395 | |
| 508490 | ASPHALT MIXING EQUIPMENT (WHOLESALE) | 38 | 46 | |
| 2951 | ASPHALT PAVING MIXTURES & BLOCKS | 1486 | 1783 | |
| 503226 | ASPHALT PRODUCTS-WHOLESALE | 41 | 49 |