CSI MasterFormat
CSI MasterFormat divisions & submittal requirements
The system that organizes construction specs and submittals — with the requirements reviewers expect for each section and the manufacturers we actually see in packages, drawn from a catalog of 335,000+ real products with data sheets.
What is CSI MasterFormat?
CSI MasterFormat is the standard for organizing construction specifications and project information in North America, published jointly by the Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC). It arranges the work of a building into numbered divisions and sections so that specifications, submittals, product data, and cost information all reference the same consistent structure.
Work is grouped into 50 division numbers (00 through 49), and each division breaks into sections identified by a six-digit code — for example, 26 05 19 sits in Division 26, Electrical. Because the specification is organized this way, reviewers expect a submittal package to follow the same order: product data, shop drawings, and samples filed under their MasterFormat section. Browse the sections below to see what belongs in a compliant submittal for each one.
Division 03 — Concrete
Division 04 — Masonry
Division 05 — Metals
Division 06 — Wood & Plastics
Division 07 — Thermal & Moisture Protection
07 21 00
Thermal Insulation
382 products · 35 manufacturers in our catalog
07 25 00
Weather Barriers
6 products · 5 manufacturers in our catalog
07 54 23
TPO Roofing
190 products · 21 manufacturers in our catalog
07 53 23
EPDM Roofing
147 products · 7 manufacturers in our catalog
07 62 00
Flashing & Sheet Metal
242 products · 32 manufacturers in our catalog
07 92 00
Joint Sealants
198 products · 38 manufacturers in our catalog
07 84 00
Firestopping
65 products · 9 manufacturers in our catalog
Division 08 — Openings
08 14 16
Flush Wood Doors
12 products · 3 manufacturers in our catalog
08 41 13
Aluminum-Framed Entrances & Storefronts
98 products · 8 manufacturers in our catalog
08 44 13
Glazed Aluminum Curtain Walls
118 products · 13 manufacturers in our catalog
08 71 00
Door Hardware
571 products · 28 manufacturers in our catalog
08 80 00
Glazing
1,087 products · 28 manufacturers in our catalog
08 90 00
Louvers & Vents
298 products · 20 manufacturers in our catalog
08 31 00
Access Doors & Panels
91 products · 16 manufacturers in our catalog
Division 09 — Finishes
09 21 16
Gypsum Board Assemblies
364 products · 23 manufacturers in our catalog
09 22 16
Non-Structural Metal Framing
101 products · 11 manufacturers in our catalog
09 30 13
Ceramic Tiling
37 products · 7 manufacturers in our catalog
09 51 13
Acoustical Panel Ceilings
183 products · 14 manufacturers in our catalog
09 65 19
Resilient Tile Flooring
119 products · 13 manufacturers in our catalog
09 68 00
Carpeting
659 products · 10 manufacturers in our catalog
09 91 23
Interior Painting
213 products · 29 manufacturers in our catalog
Division 10 — Specialties
10 14 00
Signage
979 products · 66 manufacturers in our catalog
10 21 13
Toilet Compartments
464 products · 5 manufacturers in our catalog
10 28 00
Toilet & Bath Accessories
598 products · 17 manufacturers in our catalog
10 44 00
Fire Protection Specialties
39 products · 4 manufacturers in our catalog
10 51 00
Lockers
126 products · 16 manufacturers in our catalog
Division 11 — Equipment
Division 21 — Fire Suppression
Division 22 — Plumbing
22 05 23
Valves for Plumbing Piping
723 products · 48 manufacturers in our catalog
22 11 16
Domestic Water Piping
282 products · 45 manufacturers in our catalog
22 13 16
Sanitary Waste & Vent Piping
26 products · 17 manufacturers in our catalog
22 05 29
Hangers & Supports for Plumbing
80 products · 16 manufacturers in our catalog
22 30 00
Plumbing Equipment
342 products · 23 manufacturers in our catalog
22 40 00
Plumbing Fixtures
22,108 products · 30 manufacturers in our catalog
22 11 19
Backflow Preventers
30 products · 8 manufacturers in our catalog
22 05 76
Drainage Piping Specialties
148 products · 9 manufacturers in our catalog
22 14 00
Storm Drainage
62 products · 13 manufacturers in our catalog
22 34 00
Commercial Water Heaters
59 products · 11 manufacturers in our catalog
Division 23 — HVAC
23 05 93
Testing, Adjusting & Balancing
13 products · 1 manufacturers in our catalog
23 07 13
Duct Insulation
6 products · 2 manufacturers in our catalog
23 21 13
Hydronic Piping
23 products · 7 manufacturers in our catalog
23 31 13
Metal Ducts
6,908 products · 259 manufacturers in our catalog
23 34 00
HVAC Fans
1,151 products · 46 manufacturers in our catalog
23 37 13
Diffusers, Registers & Grilles
372 products · 39 manufacturers in our catalog
23 64 00
Chillers
302 products · 26 manufacturers in our catalog
23 65 00
Cooling Towers
94 products · 19 manufacturers in our catalog
23 81 00
Computer-Room & Precision Cooling
191 products · 30 manufacturers in our catalog
23 74 13
Packaged Rooftop Units
651 products · 48 manufacturers in our catalog
23 81 26
Split-System Air Conditioners
397 products · 24 manufacturers in our catalog
23 82 00
Terminal Heating & Cooling Units
271 products · 15 manufacturers in our catalog
23 41 00
HVAC Air Filtration
56 products · 17 manufacturers in our catalog
23 54 00
Furnaces
26 products · 7 manufacturers in our catalog
23 72 00
Energy Recovery Ventilators
49 products · 8 manufacturers in our catalog
Division 25 — Integrated Automation
Division 26 — Electrical
26 05 19
Low-Voltage Conductors & Cable
743 products · 13 manufacturers in our catalog
26 05 33
Raceways & Boxes
3,034 products · 40 manufacturers in our catalog
26 24 16
Panelboards
370 products · 7 manufacturers in our catalog
26 27 26
Wiring Devices
16,880 products · 47 manufacturers in our catalog
26 28 16
Enclosed Switches & Circuit Breakers
1,455 products · 16 manufacturers in our catalog
26 32 13
Engine Generators
739 products · 28 manufacturers in our catalog
26 43 13
Surge Protective Devices
229 products · 28 manufacturers in our catalog
26 51 00
Interior Lighting
15,431 products · 249 manufacturers in our catalog
26 56 00
Exterior Lighting
4,918 products · 114 manufacturers in our catalog
26 09 23
Lighting Control Devices
951 products · 40 manufacturers in our catalog
26 52 00
Emergency & Exit Lighting
646 products · 43 manufacturers in our catalog
26 05 26
Grounding & Bonding
323 products · 14 manufacturers in our catalog
26 22 00
Low-Voltage Transformers
371 products · 30 manufacturers in our catalog
26 25 00
Busway
81 products · 5 manufacturers in our catalog
26 27 13
Electricity Metering
76 products · 6 manufacturers in our catalog
26 29 23
Variable Frequency Drives
219 products · 14 manufacturers in our catalog
26 33 00
UPS & Battery Systems
771 products · 30 manufacturers in our catalog
26 36 00
Transfer Switches
298 products · 32 manufacturers in our catalog
Division 27 — Communications
27 15 00
Structured Cabling
4,803 products · 12 manufacturers in our catalog
27 11 00
Communications Room Fittings
94 products · 7 manufacturers in our catalog
27 13 00
Fiber Backbone Cabling
141 products · 10 manufacturers in our catalog
27 21 00
Data Network Equipment
50 products · 14 manufacturers in our catalog
27 41 16
Audio-Video Systems
231 products · 28 manufacturers in our catalog
27 51 16
Public Address & Paging
74 products · 13 manufacturers in our catalog
Division 28 — Electronic Safety & Security
28 31 00
Fire Detection & Alarm
1,968 products · 33 manufacturers in our catalog
28 20 00
Video Surveillance & Access Control
1,385 products · 24 manufacturers in our catalog
28 16 00
Intrusion Detection
94 products · 9 manufacturers in our catalog
28 46 00
Mass Notification Systems
26 products · 5 manufacturers in our catalog
Division 32 — Exterior Improvements
CSI MasterFormat FAQ
What is CSI MasterFormat?
CSI MasterFormat is the standard for organizing construction specifications and project information in North America, published jointly by the Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC). It arranges the work of a building into numbered divisions and sections so that specs, submittals, product data, and cost data all reference the same consistent structure.
How do CSI MasterFormat numbers work?
Work is arranged into divisions numbered from 00 to 48, each broken into sections identified by a six-digit code — for example 26 05 19 sits in Division 26 (Electrical). The first pair is the division, and the remaining digits locate the section and subsection within it, so any spec section maps to one predictable place.
How many divisions are in CSI MasterFormat?
MasterFormat is organized into 50 division numbers (00 through 49), grouped into subgroups such as General Requirements, Facility Construction, and Facility Services. Not every number is actively used — several are reserved for future expansion — but the fixed numbering keeps the framework stable across projects.
Why does MasterFormat matter for submittals?
Submittal requirements live in the specifications, section by section. Because the spec is organized by MasterFormat, reviewers expect the submittal package to follow the same structure. Organizing product data, shop drawings, and samples by their MasterFormat section is what makes a package fast to review and hard to reject on organization alone.