Top 100 Contractors in NAICS 561611: Investigation and Personal Background Check Services, FY2023

Full ranking

Rank	Contractor	Net obligations	Share	Trend
1	HP Enterprise Services LLC Through Peraton Risk Decision Inc. Top agencies DCSA (Defense Counterintelligence and Security Agency) DHS (Department of Homeland Security)	$215,164,505	24.6%	Rank history: #7 in FY2021, #1 in FY2022, #3 in FY2024 and not on the FY2025 list; unchanged since FY2022.
2	CACI International Inc. 2 awardees, including Caci, Inc. - Federal and Caci Premier Technology, LLC Top agencies DCSA (Defense Counterintelligence and Security Agency) DHS (Department of Homeland Security)	$213,984,767	24.5%	Rank history: #1 in FY2021, #2 in FY2022, #1 in FY2024 and #2 in FY2025; unchanged since FY2022.
3	Protection Strategies Inc. Top agencies DOJ (Department of Justice) DHS (Department of Homeland Security) HHS (Department of Health and Human Services)	$34,958,712	4.0%	Rank history: #5 in FY2021, #4 in FY2022, #6 in FY2024 and #7 in FY2025; up 1 since FY2022.
4	Omniplex World Services Corp Top agencies DHS (Department of Homeland Security) SSA (Social Security Administration)	$26,687,790	3.1%	Rank history: not on the FY2021 list, #24 in FY2022, #33 in FY2024 and not on the FY2025 list; up 20 since FY2022.
5	Arctic Slope Regional Corporation Through Asrc Federal Professional Services, LLC Top agencies DCSA (Defense Counterintelligence and Security Agency)	$26,333,500	3.0%	Rank history: not on the FY2021–FY2022 lists, #4 in FY2024 and #5 in FY2025; new.
6	Asrc Federal Professional Services, LLC Top agencies DCSA (Defense Counterintelligence and Security Agency)	$26,201,909	3.0%	Rank history: #4 in FY2021, #6 in FY2022 and not on the FY2024–FY2025 lists; unchanged since FY2022.
7	Madison Associates Inc. Top agencies DOJ (Department of Justice) HHS (Department of Health and Human Services) DOS (Department of State)	$16,426,918	1.9%	Rank history: #12 in FY2021, #9 in FY2022, #8 in FY2024 and #3 in FY2025; up 2 since FY2022.
8	Professional Risk Management, Inc. Top agencies DOJ (Department of Justice)	$16,262,886	1.9%	Rank history: #13 in FY2021, #10 in FY2022, #5 in FY2024 and #4 in FY2025; up 2 since FY2022.
9	Iworks Corp Top agencies DCSA (Defense Counterintelligence and Security Agency)	$12,467,558	1.4%	Rank history: not on the FY2021–FY2022 lists, #9 in FY2024 and #9 in FY2025; new.
10	Equifax Inc. Through Equifax Workforce Solutions LLC Top agencies SSA (Social Security Administration) DCSA (Defense Counterintelligence and Security Agency) DOS (Department of State)	$11,395,364	1.3%	Rank history: #14 in FY2021, #15 in FY2022, #86 in FY2024 and not on the FY2025 list; up 5 since FY2022.
11	Five Stones Intelligence Inc. Top agencies DOJ (Department of Justice)	$10,121,155	1.2%	Rank history: #16 in FY2021, #12 in FY2022, #11 in FY2024 and #13 in FY2025; up 1 since FY2022.
12	Capital Center for Credibility Assessment Corporation Top agencies Navy (Department of the Navy) USAF (Department of the Air Force) DOJ (Department of Justice)	$7,837,969	0.9%	Rank history: #11 in FY2021, #7 in FY2022, #19 in FY2024 and #14 in FY2025; down 5 since FY2022.
13	Emsi Holding Company Through Coventbridge (USA) LLC Top agencies USDA (Department of Agriculture)	$7,829,952	0.9%	Rank history: #21 in FY2021, #14 in FY2022 and not on the FY2024–FY2025 lists; up 1 since FY2022.
14	EAP Consultants, LLC Top agencies SSA (Social Security Administration) DHS (Department of Homeland Security) USDA (Department of Agriculture)	$6,370,440	0.7%	Rank history: #18 in FY2021, #16 in FY2022, #13 in FY2024 and #21 in FY2025; up 2 since FY2022.
15	Vertical Screen, Inc. Through Fieldprint Inc. Top agencies HHS (Department of Health and Human Services) Treasury (Department of the Treasury) DHS (Department of Homeland Security)	$5,617,113	0.6%	Rank history: #28 in FY2021, #20 in FY2022, #22 in FY2024 and not on the FY2025 list; up 5 since FY2022.
16	Potomac River Group, LLC Top agencies DOJ (Department of Justice)	$5,389,345	0.6%	Rank history: #17 in FY2021, #18 in FY2022, #21 in FY2024 and #39 in FY2025; up 2 since FY2022.
17	Excygent, LLC Top agencies Treasury (Department of the Treasury)	$5,172,231	0.6%	Rank history: #24 in FY2021, #21 in FY2022 and not on the FY2024–FY2025 lists; up 4 since FY2022.
18	Information Systems & Networks Corporation Top agencies DHS (Department of Homeland Security) DOJ (Department of Justice)	$4,786,841	0.5%	Rank history: #22 in FY2021, #17 in FY2022, #24 in FY2024 and #11 in FY2025; down 1 since FY2022.
19	Blocktrace, LLC Top agencies Treasury (Department of the Treasury)	$4,457,931	0.5%	Rank history: #30 in FY2021, #22 in FY2022 and not on the FY2024–FY2025 lists; up 3 since FY2022.
20	The Ross Agency, Inc. Top agencies VA (Department of Veterans Affairs)	$4,311,040	0.5%	Rank history: #27 in FY2021, #26 in FY2022, #14 in FY2024 and #16 in FY2025; up 6 since FY2022.
21	Ho-Chunk Shared Services Company Top agencies USAF (Department of the Air Force)	$3,589,282	0.4%	Rank history: not on the FY2021–FY2022 lists, #15 in FY2024 and not on the FY2025 list; new.
22	Anasec, Inc. Top agencies DHS (Department of Homeland Security)	$3,500,964	0.4%	Rank history: #15 in FY2021, #27 in FY2022, #20 in FY2024 and #15 in FY2025; up 5 since FY2022.
23	Renzulli & Associates Inc. Top agencies DOJ (Department of Justice)	$3,437,135	0.4%	Rank history: not on the FY2021 list, #23 in FY2022 and not on the FY2024–FY2025 lists; unchanged since FY2022.
24	Global Health Assurance Partnership, LLC Top agencies USAID (US Agency for International Development)	$3,048,765	0.3%	Rank history: #25 in FY2021, #25 in FY2022, not on the FY2024 list and #45 in FY2025; up 1 since FY2022.
25	Potomac Management Solutions LLC Top agencies DHS (Department of Homeland Security) Commerce (Department of Commerce) DOJ (Department of Justice)	$2,655,237	0.3%	Rank history: #48 in FY2021, #31 in FY2022, #28 in FY2024 and #38 in FY2025; up 6 since FY2022.
26	The Washington Center for Internships and Academic Seminars Top agencies HHS (Department of Health and Human Services) Commerce (Department of Commerce) USAGM (US Agency for Global Media)	$2,451,271	0.3%	Rank history: #26 in FY2021, #30 in FY2022, #30 in FY2024 and not on the FY2025 list; up 4 since FY2022.
27	Sullivan Cove Consultants, LLC Top agencies DOJ (Department of Justice)	$2,033,012	0.2%	Rank history: #6 in FY2021, #5 in FY2022 and not on the FY2024–FY2025 lists; down 22 since FY2022.
28	S.j. Bashen, Inc. Top agencies DHS (Department of Homeland Security) HHS (Department of Health and Human Services) DCMA (Defense Contract Management Agency)	$1,858,173	0.2%	Rank history: #42 in FY2021, #38 in FY2022, #34 in FY2024 and #25 in FY2025; up 10 since FY2022.
29	DNI Emerging Technologies, LLC Top agencies HHS (Department of Health and Human Services)	$1,741,550	0.2%	Rank history: not on the FY2021–FY2022 lists, #25 in FY2024 and #26 in FY2025; new.
30	Nemean Solutions LLC Top agencies Army (Department of the Army)	$1,728,898	0.2%	Rank history: not on the FY2021–FY2022 lists, #17 in FY2024 and #23 in FY2025; new.
31	Crossroads Mediation Services, Inc. Top agencies DOT (Department of Transportation) DHS (Department of Homeland Security) USDA (Department of Agriculture)	$1,617,537	0.2%	Rank history: #29 in FY2021, #29 in FY2022, #27 in FY2024 and #29 in FY2025; down 2 since FY2022.
32	PAE Government Services Inc. Through PAE Professional Services, LLC Top agencies Army (Department of the Army) SEC (Securities and Exchange Commission) DOE (Department of Energy)	$1,565,005	0.2%	Rank history: not on the FY2021 list, #28 in FY2022 and not on the FY2024–FY2025 lists; down 4 since FY2022.
33	Chenega Defense & Aerospace Solutions, LLC Top agencies Treasury (Department of the Treasury)	$1,494,363	0.2%	Rank history: not on the FY2021–FY2022 lists, #23 in FY2024 and #22 in FY2025; new.
34	Government Retirement & Benefits, Inc. Top agencies DOI (Department of the Interior) Commerce (Department of Commerce) Treasury (Department of the Treasury)	$1,449,500	0.2%	Rank history: #38 in FY2021, #32 in FY2022, #26 in FY2024 and #27 in FY2025; down 2 since FY2022.
35	Vius, LLC Top agencies DHS (Department of Homeland Security)	$1,064,635	0.1%	Rank history: #34 in FY2021, #40 in FY2022 and not on the FY2024–FY2025 lists; up 5 since FY2022.
36	Acquisition Solutions Eagles, LLC Top agencies DHS (Department of Homeland Security)	$999,889	0.1%	Rank history: not on the FY2021 list, #42 in FY2022, not on the FY2024 list and #40 in FY2025; up 6 since FY2022.
37	Celerity Government Solutions LLC Top agencies SEC (Securities and Exchange Commission)	$998,542	0.1%	Rank history: #31 in FY2021, not on the FY2022 list and not on the FY2024–FY2025 lists; returned.
38	The Law Offices of Stuart L. Plotnick, LLC Top agencies USDA (Department of Agriculture) Commerce (Department of Commerce) DHS (Department of Homeland Security)	$879,494	0.1%	Rank history: #36 in FY2021, #37 in FY2022, #43 in FY2024 and not on the FY2025 list; down 1 since FY2022.
39	Gant Global Services (GGS) Inc. Top agencies VA (Department of Veterans Affairs) HUD (Department of Housing and Urban Development)	$867,415	0.1%	Rank history: not on the FY2021–FY2022 lists, #31 in FY2024 and #51 in FY2025; new.
40	Adept Services, Inc. Top agencies DOJ (Department of Justice)	$847,196	0.1%	Rank history: #41 in FY2021, #45 in FY2022, #50 in FY2024 and #44 in FY2025; up 5 since FY2022.
41	Key Bridge Foundation for Education and Research Top agencies DOJ (Department of Justice)	$804,672	0.1%	Rank history: #64 in FY2021, #63 in FY2022, #53 in FY2024 and #50 in FY2025; up 22 since FY2022.
42	AON Consulting Inc. Top agencies DOJ (Department of Justice)	$799,483	0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; new.
43	County of Geauga Through Geauga County Of Top agencies SSA (Social Security Administration)	$791,625	0.1%	Rank history: #52 in FY2021, #44 in FY2022, #44 in FY2024 and not on the FY2025 list; up 1 since FY2022.
44	Harris County Top agencies SSA (Social Security Administration)	$731,938	0.1%	Rank history: #77 in FY2021, #67 in FY2022, #56 in FY2024 and #60 in FY2025; up 23 since FY2022.
45	Sierra Tahoe Investigations Top agencies VA (Department of Veterans Affairs)	$727,351	0.1%	Rank history: #39 in FY2021, #57 in FY2022, #36 in FY2024 and #30 in FY2025; up 12 since FY2022.
46	Martin Miser Cody & Associates LLC Top agencies VA (Department of Veterans Affairs)	$719,000	0.1%	Rank history: #40 in FY2021, #47 in FY2022, #39 in FY2024 and #36 in FY2025; up 1 since FY2022.
47	David Jones CPA PC Top agencies VA (Department of Veterans Affairs) DOI (Department of the Interior)	$655,693	0.1%	Rank history: not on the FY2021–FY2022 lists, #35 in FY2024 and #33 in FY2025; new.
48	County of ST Louis 2 awardees, including ST. Louis County, Missouri Top agencies SSA (Social Security Administration)	$652,428	0.1%	Rank history: #55 in FY2021, #48 in FY2022, #48 in FY2024 and #46 in FY2025; unchanged since FY2022.
49	Computer Evidence Specialists, LLC Top agencies VA (Department of Veterans Affairs)	$643,917	0.1%	Rank history: #45 in FY2021, #55 in FY2022, #38 in FY2024 and #18 in FY2025; up 6 since FY2022.
50	Platinum Business Services, LLC Top agencies HHS (Department of Health and Human Services)	$627,442	0.1%	Rank history: #63 in FY2021, #62 in FY2022, #51 in FY2024 and not on the FY2025 list; up 12 since FY2022.
51	The Ravens Group, Inc. Top agencies VA (Department of Veterans Affairs)	$625,199	0.1%	Rank history: #46 in FY2021, #52 in FY2022, #41 in FY2024 and #32 in FY2025; up 1 since FY2022.
52	The Ar Group, LLC Top agencies DOI (Department of the Interior)	$593,421	0.1%	Rank history: #59 in FY2021, #65 in FY2022 and not on the FY2024–FY2025 lists; up 13 since FY2022.
53	Whooster Inc. Top agencies DHS (Department of Homeland Security) USDA (Department of Agriculture)	$529,000	0.1%	Rank history: not on the FY2021–FY2022 lists, #42 in FY2024 and #47 in FY2025; new.
54	Resolution Services, L.l.c Top agencies DOS (Department of State) Commerce (Department of Commerce) DOJ (Department of Justice)	$523,017	0.1%	Rank history: #49 in FY2021, #59 in FY2022, #61 in FY2024 and #64 in FY2025; up 5 since FY2022.
55	Venesco LLC Top agencies Navy (Department of the Navy)	$512,672	0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; new.
56	Skopenow Inc. Top agencies USAF (Department of the Air Force)	$505,992	0.1%	Rank history: not on the FY2021–FY2022 lists, #52 in FY2024 and #53 in FY2025; new.
57	Magnet Forensics, LLC Top agencies HHS (Department of Health and Human Services)	$494,450	0.1%	Rank history: #62 in FY2021, #58 in FY2022 and not on the FY2024–FY2025 lists; up 1 since FY2022.
58	Strativia LLC Top agencies CNCS (Corporation for National and Community Service)	$487,674	0.1%	Rank history: #60 in FY2021, #56 in FY2022, #60 in FY2024 and not on the FY2025 list; down 2 since FY2022.
59	Information Discovery Services, LLC Top agencies HHS (Department of Health and Human Services) SEC (Securities and Exchange Commission)	$366,629	<0.1%	Rank history: #58 in FY2021, #61 in FY2022, #65 in FY2024 and #35 in FY2025; up 2 since FY2022.
60	Creative It Solutions LLC Top agencies HHS (Department of Health and Human Services)	$363,988	<0.1%	Rank history: #33 in FY2021, #36 in FY2022 and not on the FY2024–FY2025 lists; down 24 since FY2022.
61	The Oryza Group LLC Top agencies DISA (Defense Information Systems Agency)	$350,432	<0.1%	Rank history: #66 in FY2021, #64 in FY2022 and not on the FY2024–FY2025 lists; up 3 since FY2022.
62	HR Anew Inc. Top agencies DHS (Department of Homeland Security)	$326,013	<0.1%	Rank history: not on the FY2021–FY2022 lists, #40 in FY2024 and #49 in FY2025; new.
63	Advanced EEO Solutions LLC Top agencies Navy (Department of the Navy) DOJ (Department of Justice) USDA (Department of Agriculture)	$325,086	<0.1%	Rank history: not on the FY2021 list, #84 in FY2022, #46 in FY2024 and #48 in FY2025; up 21 since FY2022.
64	Integra FEC LLC Top agencies SEC (Securities and Exchange Commission)	$291,370	<0.1%	Rank history: not on the FY2021–FY2022 lists, #78 in FY2024 and not on the FY2025 list; up 44 since FY2022.
65	City of Chicago Top agencies SSA (Social Security Administration)	$283,458	<0.1%	Rank history: #72 in FY2021, #72 in FY2022 and not on the FY2024–FY2025 lists; up 7 since FY2022.
66	Puerto Rico Commonwealth Of Through Department of Police Puerto Rico Top agencies SSA (Social Security Administration)	$279,178	<0.1%	Rank history: #70 in FY2021, #71 in FY2022 and not on the FY2024–FY2025 lists; up 5 since FY2022.
67	Inroads, Inc. Top agencies Treasury (Department of the Treasury) EXIM (Export Import Bank of the US)	$274,660	<0.1%	Rank history: #82 in FY2021, not on the FY2022 list, #57 in FY2024 and not on the FY2025 list; up 45 since FY2022.
68	The Arbinger Company Top agencies Army (Department of the Army)	$210,921	<0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; new.
69	Urbandale Forensics, P.C. Top agencies DHS (Department of Homeland Security)	$205,750	<0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; new.
70	Englert Forensics Consultants, LLC Top agencies DHS (Department of Homeland Security)	$172,358	<0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; new.
71	SF International Sociedad POR Acciones Simplificada Top agencies DOS (Department of State)	$160,687	<0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; new.
72	Serco Inc Top agencies DLA (Defense Logistics Agency)	$155,238	<0.1%	Rank history: not on the FY2021–FY2022 lists, #63 in FY2024 and not on the FY2025 list; new.
73	Business Decisions Information Inc. Top agencies DHS (Department of Homeland Security)	$153,692	<0.1%	Rank history: not on the FY2021 list, #53 in FY2022, #49 in FY2024 and #59 in FY2025; down 20 since FY2022.
74	Sharon L Floyd Top agencies Navy (Department of the Navy)	$153,541	<0.1%	Rank history: #68 in FY2021, #81 in FY2022 and not on the FY2024–FY2025 lists; up 7 since FY2022.
75	Kentech Consulting Inc. Top agencies DOJ (Department of Justice)	$151,810	<0.1%	Rank history: #47 in FY2021, #68 in FY2022, #66 in FY2024 and #62 in FY2025; down 7 since FY2022.
76	Mind Your Business Inc Top agencies DHS (Department of Homeland Security) Navy (Department of the Navy)	$145,420	<0.1%	Rank history: not on the FY2021–FY2022 lists, #73 in FY2024 and #70 in FY2025; new.
77	Greystone Advisory Group Top agencies Commerce (Department of Commerce)	$139,771	<0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; up 147 since FY2022.
78	Esposito Christopher Top agencies DOJ (Department of Justice)	$132,622	<0.1%	Rank history: not on the FY2021–FY2022 lists, #82 in FY2024 and #83 in FY2025; up 134 since FY2022.
79	Guare Dean Top agencies DOJ (Department of Justice)	$122,500	<0.1%	Rank history: #87 in FY2021, #89 in FY2022, #71 in FY2024 and #65 in FY2025; up 10 since FY2022.
80	Wilson Scott M Top agencies DOJ (Department of Justice)	$122,380	<0.1%	Rank history: #91 in FY2021, #91 in FY2022, not on the FY2024 list and #72 in FY2025; up 11 since FY2022.
81	Planning, Inc. Top agencies Treasury (Department of the Treasury)	$122,272	<0.1%	Rank history: #73 in FY2021, #80 in FY2022, #85 in FY2024 and not on the FY2025 list; down 1 since FY2022.
82	Dubois Michelle Top agencies DOJ (Department of Justice)	$121,722	<0.1%	Rank history: not on the FY2021–FY2022 lists, #83 in FY2024 and not on the FY2025 list; up 45 since FY2022.
83	Icris, LLC Top agencies Commerce (Department of Commerce) USDA (Department of Agriculture) National Gallery of Art	$120,117	<0.1%	Rank history: #56 in FY2021, #60 in FY2022, #62 in FY2024 and #56 in FY2025; down 23 since FY2022.
84	JP Investigative Associates LLC Top agencies DOJ (Department of Justice)	$120,000	<0.1%	Rank history: #96 in FY2021, #77 in FY2022, #74 in FY2024 and #67 in FY2025; down 7 since FY2022.
85	The Cordero Group LLC Top agencies DOJ (Department of Justice)	$117,451	<0.1%	Rank history: #69 in FY2021, not on the FY2022 list and not on the FY2024–FY2025 lists; up 16 since FY2022.
86	Kent Carter Investigations, LLC Top agencies DOJ (Department of Justice)	$116,000	<0.1%	Rank history: not on the FY2021–FY2022 lists, #80 in FY2024 and #81 in FY2025; new.
87	WCD Integrity Solutions LLC Top agencies DOJ (Department of Justice)	$116,000	<0.1%	Rank history: not on the FY2021–FY2022 lists, #79 in FY2024 and #79 in FY2025; new.
88	Sikich CPA LLC Top agencies CNCS (Corporation for National and Community Service)	$112,869	<0.1%	Rank history: #50 in FY2021, not on the FY2022 list and not on the FY2024–FY2025 lists; up 46 since FY2022.
89	Darnall Kenneth J Top agencies DOJ (Department of Justice)	$110,273	<0.1%	Rank history: #94 in FY2021, #97 in FY2022, #77 in FY2024 and #73 in FY2025; up 8 since FY2022.
90	Coolahan Corey Top agencies DOJ (Department of Justice)	$110,089	<0.1%	Rank history: #98 in FY2021, #78 in FY2022, #68 in FY2024 and #66 in FY2025; down 12 since FY2022.
91	Jbcn Investigations LLC Top agencies DOJ (Department of Justice)	$109,980	<0.1%	Rank history: not on the FY2021 list, #95 in FY2022, #70 in FY2024 and not on the FY2025 list; up 4 since FY2022.
92	Brandon Spears LLC Top agencies DOJ (Department of Justice)	$109,980	<0.1%	Rank history: not on the FY2021 list, #94 in FY2022, #67 in FY2024 and #68 in FY2025; up 2 since FY2022.
93	Expert Resolutions, LLC Top agencies DOJ (Department of Justice)	$107,513	<0.1%	Rank history: #97 in FY2021, #98 in FY2022, #69 in FY2024 and #69 in FY2025; up 5 since FY2022.
94	Professionally Written, L.L.C. Top agencies DHS (Department of Homeland Security)	$105,735	<0.1%	Rank history: not on the FY2021 list, #83 in FY2022, #47 in FY2024 and #78 in FY2025; down 11 since FY2022.
95	Relationship Training Institute Top agencies DHS (Department of Homeland Security)	$100,000	<0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; new.
96	Whcook Consulting Top agencies DOJ (Department of Justice)	$98,743	<0.1%	Rank history: #90 in FY2021, not on the FY2022 list and not on the FY2024–FY2025 lists; up 8 since FY2022.
97	Salen, J Richard Top agencies DOJ (Department of Justice)	$95,821	<0.1%	Rank history: #100 in FY2021, not on the FY2022 list and not on the FY2024–FY2025 lists; up 5 since FY2022.
98	Kimberly G Fetsko Top agencies DOJ (Department of Justice)	$94,470	<0.1%	Rank history: not on the FY2021 list, #100 in FY2022 and not on the FY2024–FY2025 lists; up 2 since FY2022.
99	Collier, Harry Lee JR Top agencies DOJ (Department of Justice)	$92,550	<0.1%	Rank history: #99 in FY2021, not on the FY2022 list and not on the FY2024–FY2025 lists; up 11 since FY2022.
100	Assurgent Solutions, LLC Top agencies Smithsonian (Smithsonian Institution)	$88,316	<0.1%	Rank history: not on the FY2021–FY2022 lists and not on the FY2024–FY2025 lists; up 42 since FY2022.

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 $874 million 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. 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.
• Fiscal year 2023 ran Oct 1, 2022 – Sep 30, 2023. The Department of Defense reports its contract actions to FPDS about 90 days late, so a fiscal year is ranked once they're in, in February, and the list doesn't change after.
• Rank changes compare with FY2022. "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. The step from FY2022 takes the color of the rank change beside it.
• Placeholder recipients FPDS uses when it names no company ("Miscellaneous Foreign Contractors" and the like) aren't ranked.

Quick answers