Top 100 Contractors in NAICS 561611: Investigation and Personal Background Check Services, Aug 2025–Jul 2026

Parent companies by net contract obligations Aug 1, 2025 – Jul 31, 2026 Code page on GovTribe

The latest 12 months. See the newest fiscal year's list: Top Contractors in NAICS 561611: Investigation and Personal Background Check Services, FY2025.

The top 10 won 73% of NAICS 561611 contract dollars from August 2025 through July 2026

Ranking facts

Contract obligations
$988,357,089 Net of deobligations, by contracts coded NAICS 561611
Contractors
266 Parent companies with an obligation
Largest contractor
CACI International Inc. $306 million, 29.2% of obligations
Data as of

Contract actions from FPDS (SAM.gov). How the rankings work · Download all 100 rows as CSV · Free to reuse with credit to GovTribe (CC BY 4.0)

Full ranking

Rank Contractor Net obligations Share Trend
1 $306,013,286
Rank history: #1 in FY2021, #2 in FY2022, #2 in FY2023, #1 in FY2024 and #2 in FY2025; up 1 since Aug 2024–Jul 2025.
2 $274,869,300
Rank history: not on the FY2021–FY2023 lists, #2 in FY2024 and #1 in FY2025; down 1 since Aug 2024–Jul 2025.
3 $44,987,596
Rank history: not on the FY2021–FY2022 lists, #5 in FY2023, #4 in FY2024 and #5 in FY2025; unchanged since Aug 2024–Jul 2025.
4 $27,922,360
Rank history: #13 in FY2021, #10 in FY2022, #8 in FY2023, #5 in FY2024 and #4 in FY2025; up 1 since Aug 2024–Jul 2025.
5 $26,465,345
Rank history: #12 in FY2021, #9 in FY2022, #7 in FY2023, #8 in FY2024 and #3 in FY2025; up 2 since Aug 2024–Jul 2025.
6 $23,284,534
Rank history: not on the FY2021–FY2023 lists, #10 in FY2024 and #10 in FY2025; up 4 since Aug 2024–Jul 2025.
7 $20,509,216
Rank history: #14 in FY2021, #15 in FY2022, #10 in FY2023, #86 in FY2024 and #6 in FY2025; new, not ranked in Aug 2024–Jul 2025.
8 $16,473,958
Rank history: #9 in FY2021, #8 in FY2022, #9 in FY2023, #9 in FY2024 and #9 in FY2025; down 2 since Aug 2024–Jul 2025.
9 $15,190,083
Rank history: #5 in FY2021, #4 in FY2022, #3 in FY2023, #6 in FY2024 and #7 in FY2025; down 5 since Aug 2024–Jul 2025.
10
Caduceus Healthcare Inc Through Caduceus Inc.
$11,965,000
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
11
Five Stones Intelligence Inc.
$10,769,672
Rank history: #16 in FY2021, #12 in FY2022, #11 in FY2023, #11 in FY2024 and #13 in FY2025; down 2 since Aug 2024–Jul 2025.
12 $10,492,817
Rank history: #45 in FY2021, #55 in FY2022, #49 in FY2023, #38 in FY2024 and #19 in FY2025; up 63 since Aug 2024–Jul 2025.
13 $10,431,162
Rank history: not on the FY2021–FY2024 lists and #8 in FY2025; new, not ranked in Aug 2024–Jul 2025.
14 $9,866,171
Rank history: #11 in FY2021, #7 in FY2022, #12 in FY2023, #19 in FY2024 and #14 in FY2025; down 3 since Aug 2024–Jul 2025.
15 $9,386,986
Rank history: not on the FY2021–FY2023 lists, #12 in FY2024 and #12 in FY2025; up 24 since Aug 2024–Jul 2025.
16 $9,296,302
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
17 $8,686,250
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
18 $7,690,000
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
19 $6,720,305
Rank history: not on the FY2021–FY2024 lists and #18 in FY2025; up 46 since Aug 2024–Jul 2025.
20 $6,457,561
Rank history: not on the FY2021–FY2024 lists and #17 in FY2025; new, not ranked in Aug 2024–Jul 2025.
21 $6,270,128
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
22 $6,257,598
Rank history: #15 in FY2021, #27 in FY2022, #22 in FY2023, #20 in FY2024 and #15 in FY2025; down 9 since Aug 2024–Jul 2025.
23
Blocktrace LLC
$5,546,866
Rank history: not on the FY2021–FY2023 lists, #18 in FY2024 and #20 in FY2025; down 6 since Aug 2024–Jul 2025.
24 $5,507,232
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
25 $5,236,600
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
26 $4,893,761
Rank history: not on the FY2021–FY2024 lists and #27 in FY2025; unchanged since Aug 2024–Jul 2025.
27 $4,866,256
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
28 $4,816,783
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
29 $4,770,000
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
30
Savvy Professor LLC
$4,727,750
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
31 $3,910,774
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
32 $3,798,720
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
33 $3,653,647
Rank history: #29 in FY2021, #29 in FY2022, #31 in FY2023, #27 in FY2024 and #28 in FY2025; down 6 since Aug 2024–Jul 2025.
34 $3,482,906
Rank history: #27 in FY2021, #26 in FY2022, #20 in FY2023, #14 in FY2024 and #16 in FY2025; down 20 since Aug 2024–Jul 2025.
35 $3,216,326
Rank history: #17 in FY2021, #18 in FY2022, #16 in FY2023, #21 in FY2024 and #38 in FY2025; down 1 since Aug 2024–Jul 2025.
36 $3,080,158
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
37
Nemean Solutions LLC
$2,853,703
Rank history: not on the FY2021–FY2022 lists, #30 in FY2023, #17 in FY2024 and #23 in FY2025; down 19 since Aug 2024–Jul 2025.
38 $2,812,500
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
39 $2,701,463
Rank history: not on the FY2021 list, #90 in FY2022, not on the FY2023 list, #32 in FY2024 and not on the FY2025 list; down 24 since Aug 2024–Jul 2025.
40 $2,656,328
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
41 $2,536,823
Rank history: not on the FY2021–FY2022 lists, #29 in FY2023, #25 in FY2024 and #25 in FY2025; down 17 since Aug 2024–Jul 2025.
42 $2,282,563
Rank history: #39 in FY2021, #57 in FY2022, #45 in FY2023, #36 in FY2024 and #29 in FY2025; down 7 since Aug 2024–Jul 2025.
43 $2,076,250
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
44 $2,073,250
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
45 $2,022,283
Rank history: #42 in FY2021, #38 in FY2022, #28 in FY2023, #34 in FY2024 and #24 in FY2025; down 20 since Aug 2024–Jul 2025.
46 $1,888,283
Rank history: not on the FY2021–FY2022 lists, #47 in FY2023, #35 in FY2024 and #32 in FY2025; down 15 since Aug 2024–Jul 2025.
47 $1,812,000
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
48 $1,799,413
Rank history: #38 in FY2021, #32 in FY2022, #34 in FY2023, #26 in FY2024 and #26 in FY2025; down 28 since Aug 2024–Jul 2025.
49 $1,726,647
Rank history: not on the FY2021–FY2024 lists and #30 in FY2025; new, not ranked in Aug 2024–Jul 2025.
50 $1,690,277
Rank history: not on the FY2021–FY2024 lists and #22 in FY2025; new, not ranked in Aug 2024–Jul 2025.
51 $1,649,376
Rank history: #46 in FY2021, #52 in FY2022, #51 in FY2023, #41 in FY2024 and #31 in FY2025; down 11 since Aug 2024–Jul 2025.
52 $1,624,500
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
53 $1,614,000
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
54 $1,603,384
Rank history: not on the FY2021–FY2024 lists and #33 in FY2025; down 25 since Aug 2024–Jul 2025.
55 $1,278,044
Rank history: #40 in FY2021, #47 in FY2022, #46 in FY2023, #39 in FY2024 and #35 in FY2025; down 19 since Aug 2024–Jul 2025.
56 $1,161,434
Rank history: not on the FY2021–FY2024 lists and #36 in FY2025; new, not ranked in Aug 2024–Jul 2025.
57 $1,055,544
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
58 $1,043,716
Rank history: #58 in FY2021, #61 in FY2022, #59 in FY2023, #65 in FY2024 and #34 in FY2025; down 28 since Aug 2024–Jul 2025.
59 $891,082
Rank history: not on the FY2021–FY2024 lists and #40 in FY2025; new, not ranked in Aug 2024–Jul 2025.
60 $879,199
Rank history: #52 in FY2021, #44 in FY2022, #43 in FY2023, #44 in FY2024 and not on the FY2025 list; new, not ranked in Aug 2024–Jul 2025.
61 $869,482
Rank history: not on the FY2021–FY2023 lists, #45 in FY2024 and #42 in FY2025; down 19 since Aug 2024–Jul 2025.
62 $841,479
Rank history: #56 in FY2021, #60 in FY2022, #83 in FY2023, #62 in FY2024 and #55 in FY2025; down 9 since Aug 2024–Jul 2025.
63 $774,732
Rank history: not on the FY2021–FY2022 lists, #39 in FY2023, #31 in FY2024 and #50 in FY2025; down 35 since Aug 2024–Jul 2025.
64 $767,469
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
65
GSS - Government Support Services LLC
$741,000
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
66
County of ST Louis Through ST. Louis County, Missouri
$713,372
Rank history: #55 in FY2021, #48 in FY2022, #48 in FY2023, #48 in FY2024 and #45 in FY2025; down 19 since Aug 2024–Jul 2025.
67 $697,480
Rank history: #77 in FY2021, #67 in FY2022, #44 in FY2023, #56 in FY2024 and #59 in FY2025; down 6 since Aug 2024–Jul 2025.
68 $639,312
Rank history: not on the FY2021–FY2023 lists, #64 in FY2024 and #56 in FY2025; down 14 since Aug 2024–Jul 2025.
69 $636,500
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
70 $601,847
Rank history: #41 in FY2021, #45 in FY2022, #40 in FY2023, #50 in FY2024 and #43 in FY2025; down 26 since Aug 2024–Jul 2025.
71 $538,514
Rank history: not on the FY2021 list, #84 in FY2022, #63 in FY2023, #46 in FY2024 and #47 in FY2025; down 33 since Aug 2024–Jul 2025.
72 $537,500
Rank history: not on the FY2021–FY2022 lists, #56 in FY2023, #52 in FY2024 and #52 in FY2025; down 23 since Aug 2024–Jul 2025.
73 $498,168
Rank history: #64 in FY2021, #63 in FY2022, #41 in FY2023, #53 in FY2024 and #49 in FY2025; down 30 since Aug 2024–Jul 2025.
74 $453,750
Rank history: not on the FY2021–FY2022 lists, #53 in FY2023, #42 in FY2024 and #46 in FY2025; down 42 since Aug 2024–Jul 2025.
75 $427,500
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
76 $424,251
Rank history: not on the FY2021 list, #53 in FY2022, #73 in FY2023, #49 in FY2024 and #58 in FY2025; down 20 since Aug 2024–Jul 2025.
77 $407,326
Rank history: not on the FY2021–FY2024 lists and #76 in FY2025; new, not ranked in Aug 2024–Jul 2025.
78 $369,680
Rank history: not on the FY2021–FY2024 lists and #54 in FY2025; new, not ranked in Aug 2024–Jul 2025.
79 $348,000
Rank history: not on the FY2021–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
80 $325,348
Rank history: not on the FY2021–FY2023 lists, #72 in FY2024 and #57 in FY2025; down 29 since Aug 2024–Jul 2025.
81 $279,178
Rank history: not on the FY2021–FY2024 lists and #51 in FY2025; down 26 since Aug 2024–Jul 2025.
82 $245,840
Rank history: #91 in FY2021, #91 in FY2022, #80 in FY2023, not on the FY2024 list and #71 in FY2025; new, not ranked in Aug 2024–Jul 2025.
83 $242,744
Rank history: not on the FY2021–FY2024 lists and #70 in FY2025; new, not ranked in Aug 2024–Jul 2025.
84 $224,578
Rank history: not on the FY2021–FY2023 lists, #75 in FY2024 and #96 in FY2025; down 8 since Aug 2024–Jul 2025.
85
ManTech International Corporation Through Mantech Advanced Systems International, Inc.
$210,112
Rank history: not on the FY2021–FY2024 lists and #60 in FY2025; down 25 since Aug 2024–Jul 2025.
86 $189,723
Rank history: not on the FY2021–FY2024 lists and #62 in FY2025; new, not ranked in Aug 2024–Jul 2025.
87 $168,655
Rank history: #47 in FY2021, #68 in FY2022, #75 in FY2023, #66 in FY2024 and #61 in FY2025; up 17 since Aug 2024–Jul 2025.
88 $145,196
Rank history: #87 in FY2021, #89 in FY2022, #79 in FY2023, #71 in FY2024 and #64 in FY2025; down 22 since Aug 2024–Jul 2025.
89 $144,500
Rank history: #75 in FY2021, #73 in FY2022 and not on the FY2023–FY2025 lists; new, not ranked in Aug 2024–Jul 2025.
90 $140,457
Rank history: #98 in FY2021, #78 in FY2022, #90 in FY2023, #68 in FY2024 and #65 in FY2025; down 23 since Aug 2024–Jul 2025.
91 $134,500
Rank history: not on the FY2021 list, #94 in FY2022, #92 in FY2023, #67 in FY2024 and #67 in FY2025; up 8 since Aug 2024–Jul 2025.
92 $131,810
Rank history: #97 in FY2021, #98 in FY2022, #93 in FY2023, #69 in FY2024 and #68 in FY2025; down 21 since Aug 2024–Jul 2025.
93 $131,810
Rank history: #96 in FY2021, #77 in FY2022, #84 in FY2023, #74 in FY2024 and #66 in FY2025; down 25 since Aug 2024–Jul 2025.
94 $123,822
Rank history: not on the FY2021–FY2023 lists, #88 in FY2024 and #73 in FY2025; down 35 since Aug 2024–Jul 2025.
95 $115,565
Rank history: not on the FY2021–FY2024 lists and #74 in FY2025; down 23 since Aug 2024–Jul 2025.
96 $108,728
Rank history: not on the FY2021 list, #87 in FY2022, not on the FY2023 list, #76 in FY2024 and #75 in FY2025; down 38 since Aug 2024–Jul 2025.
97 $105,912
Rank history: not on the FY2021–FY2022 lists, #87 in FY2023, #79 in FY2024 and #78 in FY2025; down 40 since Aug 2024–Jul 2025.
98 $105,502
Rank history: not on the FY2021–FY2022 lists, #86 in FY2023, #80 in FY2024 and #80 in FY2025; down 36 since Aug 2024–Jul 2025.
99 $101,760
Rank history: not on the FY2021–FY2022 lists, #78 in FY2023, #82 in FY2024 and #82 in FY2025; down 36 since Aug 2024–Jul 2025.
100 $91,834
Rank history: not on the FY2021–FY2023 lists, #87 in FY2024 and #79 in FY2025; down 22 since Aug 2024–Jul 2025.
Show 75 more

100 of 266 contractors listed here. See the rest on GovTribe.

How this ranking works

  • Source: every contract action FPDS records (as published on SAM.gov) in the period, as GovTribe received it.
  • Amounts are net obligations: what was obligated, less what was deobligated. Shares are of $1.05 billion obligated before deobligations, so they never pass 100%.
  • Parent companies: each action counts under the ultimate parent its award record names, or under the awardee when it names none, so no dollar counts twice. An awardee whose own actions mostly name no parent, and that no other company's actions name as their parent, rolls up its SAM.gov registration's chain of parent companies: it counts under the first company there that other companies' actions name as their parent, or under the parent most of a company's own actions name, whichever comes first; with neither, under the highest company in the chain with federal contracts of its own. Joint ventures stay companies of their own. Parents of the same name (Inc., LLC and the like aside) count as one company, since FPDS records a company's parent under more than one UEI over time. GovTribe corrects a few parents and names by hand; see the corrections.
  • Period: the trailing 12 months end with the last month that ended at least 90 days ago, because the Department of Defense reports its contract actions to FPDS about 90 days late. The list is rebuilt each night.
  • Rank changes compare with Aug 2024–Jul 2025. "New" marks a company outside that period's top 500, and "Returned" one of those that was on an earlier fiscal year's list.
  • Rank lines show each company's rank on every fiscal year's list since FY2021, #1 at the top, on a scale that gives the top of the list more room. A dashed stretch spans years it wasn't on the list.
  • Placeholder recipients FPDS uses when it names no company ("Miscellaneous Foreign Contractors" and the like) aren't ranked.

Quick answers

Who were the top 10 NAICS 561611 contractors in Aug 2025–Jul 2026?

1. CACI International Inc. ($306M), 2. Peraton Risk Decision Inc. ($275M), 3. Arctic Slope Regional Corporation ($45M), 4. Professional Risk Management, Inc. ($27.9M), 5. Madison Associates Inc. ($26.5M), 6. Constellis, LLC ($23.3M), 7. Equifax Inc. ($20.5M), 8. Iworks Corp ($16.5M), 9. Protection Strategies Inc. ($15.2M), 10. Caduceus Healthcare Inc ($12M).

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