NAICS Code 561621: Security Systems Services (except Locksmiths)
National industry
SBA small business size standard: $25 million in average annual receipts
Definition
This U.S. industry comprises establishments primarily engaged in (1) selling security alarm systems, such as burglar and fire alarms, along with installation, repair, or monitoring services or (2) remote monitoring of electronic security alarm systems.
Code facts
- Part of
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56
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561
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5616
- 56162
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5616
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561
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56
- Contract awards
- 1,153 In the last 12 months
- Contract obligations
- $781,545,319 In FY2025
NAICS codes and definitions come from the U.S. Census Bureau, size standards from the SBA and contract spending from SAM.gov/FPDS.
Business activities under NAICS 561621
- Alarm system monitoring services
- Alarm systems sales combined with installation, repair, or monitoring services
- Burglar alarm monitoring services
- Burglar alarm sales combined with installation, repair, or monitoring services
- Fire alarm monitoring services
- Fire alarm sales combined with installation, repair, or monitoring services
- Security alarm systems sales combined with installation, repair, or monitoring services
- Security system monitoring services
Looking for another activity? Search the NAICS code lookup or browse business activities from A to Z.
Contract obligations by fiscal year
| Fiscal year | Obligated |
|---|---|
| FY2027 To date | $2,459,507 |
| FY2026 | $665,672,559 |
| FY2025 | $781,545,319 |
| FY2024 | $804,540,301 |
| FY2023 | $758,334,087 |
Top contractors by obligations
| Rank | Contractor | Obligated, FY2026–FY2027 | Share |
|---|---|---|---|
| 1 | M.c. Dean, Inc. | $97,266,447 | |
| 2 | Serco Inc. | $80,213,717 | |
| 3 | Johnson Controls Security Solutions LLC | $43,600,224 | |
| 4 | Caci International Inc. | $35,755,934 | |
| 5 | Paragon Systems Inc. | $35,636,169 | |
| 6 | Johnson Controls Building Automation Systems, LLC | $25,129,163 | |
| 7 | First Coast Security Solutions, Inc. | $19,140,669 | |
| 8 | Chenega Integrated Security Solutions, LLC | $17,207,429 | |
| 9 | Triple Canopy Inc. | $15,932,362 | |
| 10 | Xator LLC | $14,323,501 |
See the full FY2025 ranking of NAICS 561621 contractors, by parent company.
Top funding agencies by obligations
| Rank | Agency | Obligated, FY2026–FY2027 | Share |
|---|---|---|---|
| 1 | Department of the Navy | $125,246,679 | |
| 2 | Department of Homeland Security | $122,167,309 | |
| 3 | Air Force | $105,149,748 | |
| 4 | Department of Transportation | $51,292,225 | |
| 5 | Department of Veterans Affairs | $49,317,311 | |
| 6 | Department of the Army | $34,167,418 | |
| 7 | Administrative Office of the U.S. Courts | $31,662,536 | |
| 8 | Department of Defense | $25,052,532 | |
| 9 | Department of Justice | $19,271,503 | |
| 10 | Securities and Exchange Commission | $15,010,905 |
Top PSC codes by obligations
| Rank | PSC code | Obligated, FY2026–FY2027 | Share |
|---|---|---|---|
| 1 | 6350 Miscellaneous Alarm, Signal, and Security Detection Systems | $166,903,552 | |
| 2 | J059 Maintenance, Repair and Rebuilding of Equipment: Electrical and Electronic Equipment Components | $91,991,464 | |
| 3 | S206 Guard Services | $86,849,994 | |
| 4 | J063 Maintenance, Repair and Rebuilding of Equipment: Alarm, Signal, and Security Detection Systems | $86,188,895 | |
| 5 | N063 Installation of Equipment: Alarm, Signal, and Security Detection Systems | $73,549,941 | |
| 6 | R499 Other Professional Services | $36,101,375 | |
| 7 | R430 Support – Professional: Physical Security and Badging | $19,467,669 | |
| 8 | J012 Maintenance, Repair and Rebuilding of Equipment: Fire Control Equipment | $17,330,643 | |
| 9 |
R408 Program Management/ |
$8,570,558 | |
| 10 | 5810 Communications Security Equipment and Components | $5,957,261 |
Contract obligations by state
| Rank | Place of performance | Obligated, last 12 months | Share |
|---|---|---|---|
| 1 | Virginia | $158,644,508 | |
| 2 | California | $147,415,541 | |
| 3 | District of Columbia | $58,101,599 | |
| 4 | Maryland | $52,872,962 | |
| 5 | Massachusetts | $19,954,248 | |
| 6 | Michigan | $18,434,997 | |
| 7 | Florida | $17,821,772 | |
| 8 | Texas | $16,146,720 | |
| 9 | New York | $12,626,305 | |
| 10 | South Carolina | $11,346,079 | |
| 11 | Hawaii | $10,105,856 | |
| 12 | Georgia | $9,730,760 | |
| 13 | Pennsylvania | $8,434,581 | |
| 14 | Colorado | $7,153,265 | |
| 15 | Washington | $6,876,153 | |
| 16 | Illinois | $6,200,036 | |
| 17 | Alabama | $4,876,021 | |
| 18 | Arizona | $4,102,064 | |
| 19 | Puerto Rico | $3,538,370 | |
| 20 | Louisiana | $3,391,568 | |
| 21 | New Jersey | $3,379,449 | |
| 22 | North Carolina | $3,219,543 | |
| 23 | Kansas | $2,823,299 | |
| 24 | Alaska | $2,765,117 | |
| 25 | Ohio | $2,518,751 | |
| 26 | Montana | $2,507,293 | |
| 27 | Oklahoma | $2,424,808 | |
| 28 | Missouri | $2,375,794 | |
| 29 | Guam | $2,023,273 | |
| 30 | Rhode Island | $2,000,944 | |
| 31 | Arkansas | $1,920,733 | |
| 32 | North Dakota | $1,772,002 | |
| 33 | Utah | $1,758,167 | |
| 34 | Wisconsin | $1,756,344 | |
| 35 | Kentucky | $1,609,004 | |
| 36 | Nebraska | $1,406,557 | |
| 37 | South Dakota | $1,293,539 | |
| 38 | West Virginia | $1,261,451 | |
| 39 | Tennessee | $1,087,910 | |
| 40 | Connecticut | $1,076,192 | |
| 41 | Minnesota | $1,030,470 | |
| 42 | Nevada | $921,879 | |
| 43 | New Mexico | $853,742 | |
| 44 | Mississippi | $830,539 | |
| 45 | Idaho | $747,953 | |
| 46 | Indiana | $738,793 | |
| 47 | New Hampshire | $482,902 | |
| 48 | Oregon | $409,090 | |
| 49 | Wyoming | $392,975 | |
| 50 | Maine | $337,979 | |
| 51 | Iowa | $187,277 | |
| 52 | Vermont | $167,110 | |
| 53 | U.S. Virgin Islands | $113,570 |
Show all 53
Shares are of everything obligated under NAICS 561621 in the last 12 months before deobligations, including work performed abroad or with no place of performance on record.
Contract opportunities
Show 39 more
Latest 49 of 14,887 listed here. See the rest on GovTribe.
Size standard history
Federal Register rules that named this code
Proposed size standard changes
| Proposed rule | Published | Comments |
|---|---|---|
| Small Business Size Standards: Monetary-Based Industry Size Standards | Closed Oct 21, 2025No final rule found |
From the NAICS codes each rule's amendments to 13 CFR 121.201 name. Rules that print their size standard tables as images aren't listed.
Quick answers
What is NAICS 561621?
NAICS 561621 is Security Systems Services (except Locksmiths), a national industry in NAICS 56, Administrative and Support and Waste Management and Remediation Services.
What is the NAICS code for fire alarm monitoring services?
The NAICS code for fire alarm monitoring services is 561621, Security Systems Services (except Locksmiths).
What is the NAICS code for alarm system monitoring services?
The NAICS code for alarm system monitoring services is 561621, Security Systems Services (except Locksmiths).
What is the NAICS code for burglar alarm monitoring services?
The NAICS code for burglar alarm monitoring services is 561621, Security Systems Services (except Locksmiths).
When did the size standard for NAICS 561621 last change?
The most recent Federal Register rule on record that names NAICS 561621 in the SBA's size standards is "Small Business Size Standards: Adjustment of Monetary-Based Size Standards, Disadvantage Thresholds, and 8(a) Eligibility Thresholds for Inflation" (87 FR 69118), published Nov 17, 2022 and effective Dec 19, 2022.
How much do federal agencies spend under NAICS 561621?
Federal contracts under NAICS 561621 obligated $781,545,319 in fiscal year 2025 and $3,012,551,773 in fiscal years 2023 through 2027.
Who are the largest contractors under NAICS 561621?
The contractors with the most obligated under NAICS 561621 in fiscal years 2026 and 2027 are M.c. Dean, Inc. ($97,266,447); Serco Inc. ($80,213,717); and Johnson Controls Security Solutions LLC ($43,600,224).
Which agencies buy the most under NAICS 561621?
The agencies that obligated the most under NAICS 561621 in fiscal years 2026 and 2027 are Department of the Navy ($125,246,679), Department of Homeland Security ($122,167,309) and Air Force ($105,149,748).
Which PSC codes are used with NAICS 561621?
The PSC codes with the most obligated under NAICS 561621 in fiscal years 2026 and 2027 are 6350 Miscellaneous Alarm, Signal, and Security Detection Systems; J059 Maintenance, Repair and Rebuilding of Equipment: Electrical and Electronic Equipment Components; and S206 Guard Services.
Where is the work under NAICS 561621 performed?
By place of performance, the states with the most contract obligations under NAICS 561621 over the last 12 months are Virginia ($158,644,508), California ($147,415,541) and the District of Columbia ($58,101,599).
What is the latest contract opportunity under NAICS 561621?
The latest contract opportunity under NAICS 561621 is Notice of Intent to Award Sole Source: Lackland AFB Modernization, special notice from Lifecycle Management Center (AFMC), posted November 5, 2026.
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