Occupational Title | Brief Number | HOC Code |
| Machine Builders (machinists) | 32 | RIE |
| Machine Molders (foundry production) | 374 | RIE |
| Machine Operators (firearms industry) | 399 | RCE |
| Machine Operators (sporting goods production) | 567 | RCE |
| Machine Rubbers (furniture manufacturing) | 373 | RCS |
| Machine Sanders (furniture manufacturing) | 373 | RCE |
| Machine Shop Setup Operators | 434 | RIE |
| Machine Tool Operators | 37 | RIE |
| Machine Tryout Setters (machinists) | 32 | RIS |
| Machinists | 32 | RIE |
| Machinists (aerospace workers) | 509 | RIE, RIS |
| Machinists, All-around | 32 | RIE |
| Machinists, Experimental | 32 | RIS |
| Machinists (firearms industry) | 399 | RIE |
| Machinists, Maintenance | 32 | RIE |
| Machinists, Marine (pleasure craft boatbuilders) | 661 | RSE |
| Machinists, Prototype | 32 | RIS |
| Macroeconomists | 233 | IAS |
| Magicians (variety performers) | 607 | AES |
| Magistrates | 339 | ESA |
| Maids (executive housekeepers) | 358 | CRE |
| Maids (household service) | 232 | no code |
| Mail Clerks | 335 | CRE |
| Mail Clerks (office) | 3 | CRE |
| Mail Handlers (postal service) | 220 | RSC |
| Maintenance Carpenters | 86 | REI |
| Maintenance Electricians | 395 | RCI |
| Maintenance Machinists | 32 | RIE |
| Maintenance Superintendents | 301 | ERI |
| Maintenance Technicians (cable television) | 244 | REC |
| Maintenance Workers, Grounds (landscapers) | 451 | RCE |
| Makeup Artists (cosmetologists) | 7 | AER |
| Makeup Artists (stage production technical staff) | 675 | AER |
| Management Accountants | 63 | CIE |
| Management Analysts | 136 | ICR |
| Management Analysts (temporary workers) | 674 | ICR |
| Management Consultants | 136 | ICR |
| Management Development Specialists | 572 | ESR, SEC |
| Management Dietitians | 76 | ESI |
| Management Trainees | 579 | ESR |
| Managers, Administrative | 605 | ESR |
| Managers, Agency (advertising) | 113 | AES |
| Managers, Airport | 457 | ESR |
| Managers, Asset | 122 | ESR |
| Managers, Assistant Lodging | 350 | ESR |
| Managers, Bed (fish farm) | 190 | ESA |
| Managers, Benefits (human resources) | 258 | ESC |
| Managers, Box Office (theatrical production) | 612 | SEC |
| Managers, Building | 459 | ERS |
| Managers, Carwash | 589 | RES |
| Managers, City | 445 | SEC |
| Managers, Community | 122 | ESR |
| Managers, Company (theatrical production) | 612 | SEC |
| Managers, Compensation (human resources) | 258 | ESR |
| Managers, Construction | 324 | ERS |
| Managers, Contract | 215 | ESA |
| Managers, Convention | 130 | ESA, ESI |
| Managers, Convention Services (lodging) | 350 | ESA |
| Managers, County | 445 | SEC |
| Managers, Credit | 362 | ESC |
| Managers, Cultural Resource | 343 | IRE |
| Managers, Dairy Farm | 223 | ESR |
| Managers, Department | 673 | ESC |
| Managers, Education and Training (human resources) | 258 | EIS |
| Managers, Employee Welfare (human resources) | 258 | SEA |
| Managers, Employment Firm | 402 | ESC |
| Managers, Employment (human resources) | 258 | ESC |
| Managers, Export-Import | 403 | ESA |
| Managers, Facility | 605 | ESR |
| Managers, Facility | 685 | ESR, RIE |
| Managers, Farm (crop) | 483 | ESR |
| Managers (fast-food) | 340 | SER |
| Managers, Food and Beverage (lodging) | 350 | ESR |
| Managers, Food Service | 100 | ESR |
| Managers, Front Office (lodging) | 350 | ESR |
| Managers, Gaming | 577 | ESR |
| Managers, General (lodging) | 350 | ESR |
| Managers, General (theatrical production) | 612 | SEC |
| Managers, Grain Elevator | 140 | EIS |
| Managers, Grounds (landscapers) | 451 | RES |
| Managers, Hatchery (fish farm) | 190 | ESA |
| Managers, Health Club (fitness) | 282 | ESR |
| Managers, House (theatrical production) | 612 | ESR |
| Managers, Human Resources | 258 | SEC |
| Managers, Industrial Traffic | 115 | ESC |
| Managers, Information Systems | 77 | SEI |
| Managers, Kitchen | 33 | ESR |
| Managers, Labor Relations (human resources) | 258 | ESR |
| Managers, Lodging | 350 | ESR |
| Managers, Lodging Recreational | 350 | SER |
| Managers, Logistics | 115 | ESC |
| Managers, Loss Prevention | 650 | ESA |
| Managers, Manufactured Housing Community | 520 | ESR |
| Managers, Marketing | 633 | AES |
| Managers, Marketing (advertising agency) | 113 | AES |
| Managers, Merchandise (retail buyers) | 95 | ESR |
| Managers, Nursery | 99 | ESA |
| Managers, Office (congressional aides) | 525 | ESR |
| Managers, Park | 470 | ERA |
| Managers, Personal (literary agents) | 325 | ESC, SEA |
| Managers, Print Production (advertising agency) | 113 | ASE |
| Managers, Production (apparel industry) | 35 | ESR |
| Managers, Project | 324 | ERS |
| Managers, Project | 472 | RSE |
| Managers, Property | 122 | ESR |
| Managers, Public Relations | 172 | ASE |
| Managers, Research (marketing researchers) | 254 | ERI |
| Managers, Restaurant | 100 | ESR |
| Managers, Retail | 673 | ESC |
| Managers, Risk | 650 | ESA |
| Managers, Safety (professionals) | 420 | IES |
| Managers, Sales | 442 | ESA |
| Managers, Sales (radio & television broadcasting) | 428 | ESA |
| Managers, Site | 122 | ESR |
| Managers, Stage (production technical staff) | 675 | ESC |
| Managers, Station (radio & television broadcasting) | 428 | ESR |
| Managers, Supermarket | 367 | ESC |
| Managers, Theater (motion picture) | 70 | ESR |
| Managers, Town | 445 | SEC |
| Managers, Traffic (radio & television broadcasting) | 428 | CRS |
| Managing Editors (publishing) | 231 | AES, CIA |
| Manicurists | 602 | ESC |
| Manipulator Operators (forge shop) | 352 | RCE |
| Manipulators (iron & steel industry) | 305 | RSE |
| Manufactured Home Assemblers | 487 | RES |
| Manufactured Home Installers | 487 | RES |
| Manufactured Home Salespersons | 78 | ESA |
| Manufactured Housing Community Managers | 520 | ESR |
| Manufacturers' Representatives | 417 | ESA |
| Manufacturing Engineers | 542 | IRE |
| Manufacturing Engineers (aerospace) | 159 | REI |
| Marble Setters | 418 | RIE |
| Marine Animal Trainers | 508 | RES, SEC |
| Marine Architects (marine engineers) | 163 | IRE |
| Marine Biologists | 543 | IRE |
| Marine Biologists (oceanographers) | 200 | no code |
| Marine Chemists | 200 | IRE, IRS |
| Marine Corps Personnel | 439 | no code |
| Marine Drafters | 22 | IRE |
| Marine Engineers | 163 | IRE |
| Marine Engineers | 200 | IRE, IRS |
| Marine Equipment Mechanics (small engine) | 683 | RES |
| Marine Geologists | 200 | IRE, IRS |
| Marine Geologists | 129 | IRE |
| Marine Machinists (pleasure craft boatbuilders) | 661 | RSE |
| Marine Oilers (merchant mariners) | 379 | REI |
| Markers (apparel industry) | 35 | CSE |
| Markers (dry cleaning) | 34 | REC |
| Marketing Directors (lodging) | 350 | SER |
| Marketing Managers | 633 | AES |
| Marketing Managers (advertising agency) | 113 | AES |
| Marketing Representatives (publishing) | 231 | ASE |
| Marketing Researchers | 254 | ISC |
| Marriage and Family Therapists | 630 | SAE |
| Marshals, Deputy U.S. | 676 | SEC |
| Marshals, Fire (petroleum refining) | 188 | ERS |
| Martial Arts Instructors | 422 | ESR |
| Masons | 10 | no code |
| Masons, Cement | 581 | RES |
| Massage Therapists | 596 | RES |
| Masseurs/Masseuses | 596 | RES |
| Mastectomy Fitters | 601 | RSE |
| Master Electricians (stage production technical staff) | 675 | AES |
| Master Plumbers | 43 | REI |
| Masters (merchant mariners) | 379 | ERI |
| Masters, Property (motion picture industry) | 2 | ERS |
| Masters, Prop (stage production technical staff) | 675 | REI |
| Matchout Workers (laundry) | 79 | CRS |
| Material Handlers | 384 | REI |
| Materials Engineers | 256 | REI |
| Materials Engineers (aerospace) | 159 | REI |
| Materials Planners | 599 | REI |
| Materials Scientists (engineers) | 256 | IRE |
| Maternal-Fetal Medicine Specialists (obstetrician-gynecologists) | 578 | IRS |
| Mates (merchant mariners) | 379 | ERS |
| Mathematical Statisticians | 165 | IRE |
| Mathematical Technicians | 162 | IRC |
| Mathematicians | 162 | IER |
| Mathematicians, Applied | 162 | IER |
| Mathematicians, Theoretical | 162 | IER |
| Measurement and Signature Intelligence Workers | 626 | AES, ERS |
| Measuring Machine Operators (leather tanning & finishing) | 297 | CRE |
| Meat Boners (slaughtering & meat-packing production) | 423 | REC |
| Meatcutters (slaughtering & meat-packing production) | 423 | RSE |
| Meat Grinders (slaughtering & meat-packing production) | 423 | RES |
| Meat Scientists | 238 | IRS |
| Mechanical Door Repairers (elevator installers) | 286 | REI |
| Mechanical Drafters | 22 | IRE |
| Mechanical Engineering Technicians | 103 | IRE |
| Mechanical Engineering Technologists | 103 | IRE |
| Mechanical Engineers | 326 | RIS |
| Mechanical Saw Operators (mining industry) | 187 | RCI |
| Mechanics, Aircraft | 182 | RIE |
| Mechanics, Automobile | 45 | RCI |
| Mechanics, Diesel | 125 | REI |
| Mechanics, Farm Equipment | 202 | RES |
| Mechanics, Front-end (automobile) | 45 | RCS |
| Mechanics, Industrial Machinery | 315 | RIC |
| Mechanics, Marine Equipment (small engine) | 683 | RES |
| Mechanics, Motorboat (small engine) | 683 | RES |
| Mechanics, Motorcycle (small engine) | 683 | RIE |
| Mechanics, Small Engine | 683 | REC |
| Media Buyers (advertising agency) | 113 | ESC |
| Media Directors (advertising agency) | 113 | ESC |
| Media Specialists (librarians) | 82 | ESA |
| Mediators (arbitrators) | 609 | ESA |
| Medical Assistants | 5 | SCR |
| Medical Assistants, Chiropractic | 5 | SRE |
| Medical Assistants, Ophthalmic | 5 | CIS |
| Medical Assistants, Podiatric | 5 | SCE |
| Medical Examiners | 332 | ISE |
| Medical Geographers | 155 | IRE |
| Medical Helicopter Dispatchers | 180 | CSE |
| Medical Illustrators | 289 | AIE |
| Medical Imaging Engineers | 519 | IRE |
| Medical Laboratory Technicians (technologists) | 16 | ISA |
| Medical Language Specialists | 580 | CSE |
| Medical and Public Health Social Workers | 84 | ESA |
| Medical Records Technicians | 681 | CIR |
| Medical Secretaries | 19 | CES |
| Medical Sociologists | 316 | IES |
| Medical Stenographers | 580 | CSE |
| Medical Technologists | 16 | ISA |
| Medical Toxicologists | 569 | IRC, IRE |
| Medical Transcribers | 580 | CSE |
| Medical Transcriptionists | 580 | CSE |
| Medical Writers | 57 | IRS |
| Melters (foundry production) | 374 | RSE |
| Melter Supervisors (iron & steel industry) | 305 | ERS |
| Melt Technicians (foundry production) | 374 | RSE |
| Member Services Counselors (ticket agents) | 333 | SEC |
| Membership Services Personnel (association executives) | 549 | ESA |
| Memorial Designers | 489 | AER |
| Menders (dry cleaning) | 34 | CRE |
| Menders (laundry) | 79 | CRE |
| Mental Health Assistants (psychiatric technicians) | 278 | SEC |
| Mental Health Counselors | 655 | SEC |
| Mental Health and Substance Abuse Social Workers | 84 | SEA |
| Merchandise Brokers (manufacturer's representatives) | 417 | ESC |
| Merchandise Displayers | 127 | ARE |
| Merchandise Distributors | 108 | RCE |
| Merchandise Managers (retail buyers) | 95 | ESR |
| Merchant Mariners | 379 | no code |
| Messengers | 647 | CES |
| Metallurgical Engineers (materials) | 256 | IRE |
| Metallurgical Engineers (mining) | 312 | IRE |
| Metallurgists | 62 | no code |
| Metallurgists, Extractive | 62 | IRE |
| Metallurgists, Physical | 62 | IRE |
| Metallurgists, Powder | 62 | no code |
| Metallurgists, Process | 62 | IRE |
| Metal and Plastic Workers (motor vehicle & parts manufacturing) | 376 | RCI |
| Metalworking Machine Operators | 37 | RIE |
| Metalworking Machine Setup Operators | 434 | RIE |
| Meteorologists | 143 | IRS |
| Meteorologists, Dynamic | 143 | IRS |
| Meteorologists, Physical | 143 | IRS |
| Meter Readers (public utilities service representatives) | 270 | CSE |
| Microbiologists | 135 | IRA |
| Microbiologists (biotechnologists) | 634 | IAR |
| Microbiologists, Public Health | 135 | ISC |
| Microbiologists, Public Health | 495 | ISC |
| Microeconomists | 233 | IAS |
| Microphone Boom Operators (motion picture industry) | 2 | RES |
| Middle School Counselors | 145 | SAE |
| Middle School Teachers | 97 | SAE |
| Midwives, Direct Entry | 475 | SIR |
| Midwives, Nurse | 475 | SIR |
| Migrant Workers (crop farmers) | 483 | REC |
| Mill Operators (leather tanning & finishing) | 297 | REC |
| Millwrights | 106 | RES |
| Mimes (variety performers) | 607 | AEI |
| Mineralogists (geologists) | 129 | ISR |
| Miners (industry workers) | 187 | RIE |
| Mining Engineers | 312 | RIE |
| Mining Industry Workers | 187 | no code |
| Mining Safety Engineers | 312 | REI |
| Ministers | 264 | SAE |
| Missionaries | 440 | SAE |
| Missionaries | 264 | SAE |
| Mission Specialists | 192 | IRS |
| Mixers (cosmetics industry) | 622 | RIE |
| Mixers (industrial chemicals production) | 369 | RES |
| Mixers, Rerecording (motion picture industry) | 2 | RSE |
| Mixers, Sound (recording industry) | 317 | RCS |
| Mixing-Machine Tenders (cosmetics industry) | 622 | RIE |
| Model Makers (pottery & porcelain ware industry) | 137 | RAE |
| Models | 61 | EAS |
| Models, Commercial | 61 | EAS |
| Models, Fashion | 61 | EAS |
| Modern Dancers | 394 | AER |
| Molders (cosmetics industry) | 622 | REC |
| Molders, Foam Rubber (rubber goods production) | 328 | RES |
| Molders (foundry production) | 374 | RIE |
| Molders, Inflated Ball (sporting goods production) | 567 | RES |
| Molecular Biologists (biotechnologists) | 634 | IAR |
| Monetary Economists | 233 | IAS |
| Mortgage Loan Officers | 443 | SEI |
| Morticians (funeral directors) | 38 | RIS |
| Motion Picture Cartoonists | 124 | AES |
| Motion Picture Industry Artists | 262 | no code |
| Motion Picture Industry Technical Staff | 2 | no code |
| Motion Picture Producers | 262 | ESA |
| Motion Picture Theater Workers | 70 | no code |
| Motorboat Mechanics (small engine) | 683 | RES |
| Motorcycle Mechanics (small engine) | 683 | RIE |
| Motor Vehicle and Parts Manufacturing Workers | 376 | no code |
| Movement Therapists | 386 | ASI |
| Movers, Household Goods | 349 | RES |
| Movers, Structural | 472 | RSE |
| Mud Loggers (petroleum drilling) | 263 | RCS |
| Multimedia Computer Specialists | 117 | AES |
| Multiplayer Networking Programmers | 678 | IRC |
| Municipal Arborists | 291 | REI |
| Museum Technicians (curators) | 393 | REI |
| Musicians, Instrumental | 80 | ASC |
| Music Teachers | 236 | AES |
| Music Therapists | 460 | SAE |
| Mycologists (botanists) | 635 | IRS |
| Mycologists (microbiologists) | 135 | IRS |