Top 100 Contractors in PSC Z1: Maintenance, Alteration, Repair Buildings, FY2024

Name: Top 100 Contractors in PSC Z1: Maintenance, Alteration, Repair Buildings, FY2024
Creator: GovTribe

Parent companies by net contract obligations Oct 1, 2023 – Sep 30, 2024 Code page on GovTribe

The top 10 won 23% of FY2024 PSC Z1 contract dollars

Contract obligations: $7,969,920,197 Net of deobligations, by contracts coded PSC Z1 or a code under it
Contractors: 3,606 Parent companies with an obligation
Largest contractor: Great Lakes Dredge & Dock Corporation $516 million, 6.0% of obligations
Data as of: Oct 14, 2026

Contract actions from FPDS (SAM.gov). How the rankings work · Download all 100 rows as CSV

Full ranking

Rank	Contractor	Net obligations	Share	Trend
1	Great Lakes Dredge & Dock Corporation Top agencies Army (Department of the Army)	$515,830,619	6.0%	Rank history: #28 in FY2021, #4 in FY2022, #5 in FY2023 and #2 in FY2025; up 4 since FY2023.
2	Amentum Services, Inc. 5 awardees, including Central Plateau Cleanup Company, LLC, URS Federal Services International, Inc. and Amentum Design and Facility Management Top agencies DOE (Department of Energy) DTRA (Defense Threat Reduction Agency) NASA (National Aeronautics and Space Administration)	$496,718,588	5.8%	Rank history: #1 in FY2021, #1 in FY2022, #1 in FY2023 and not on the FY2025 list; down 1 since FY2023.
3	J & J Maintenance Inc. 3 awardees, including J&J and Alms Mission Support Solutions, LLC Top agencies Army (Department of the Army) DHA (Defense Health Agency) Navy (Department of the Navy)	$241,185,961	2.8%	Rank history: #3 in FY2021, #2 in FY2022, #3 in FY2023 and #3 in FY2025; unchanged since FY2023.
4	Peter Kiewit Sons', Inc. 3 awardees, including Weeks Marine, Inc. and Healy Tibbitts Builders, Inc. Top agencies Army (Department of the Army)	$163,171,374	1.9%	Rank history: not on the FY2021–FY2022 lists, #45 in FY2023 and #7 in FY2025; up 41 since FY2023.
5	General Dynamics Corporation 4 awardees, including General Dynamics Mission Systems, Inc. and General Dynamics Land Systems Inc. Top agencies DHS (Department of Homeland Security) Army (Department of the Army)	$102,952,745	1.2%	Rank history: #16 in FY2021, #5 in FY2022, #12 in FY2023 and #5 in FY2025; up 7 since FY2023.
6	Facility Services Management, Inc. 2 awardees, including FSI Construction, LLC Top agencies Army (Department of the Army) DHA (Defense Health Agency) Navy (Department of the Navy)	$99,055,798	1.2%	Rank history: #24 in FY2021, #21 in FY2022, #6 in FY2023 and #12 in FY2025; unchanged since FY2023.
7	Arctic Slope Regional Corporation 6 awardees, including Asrc Federal Facilities Logistics LLC, Netcentric Technology, LLC and Asrc Communications, Ltd. Top agencies USAF (Department of the Air Force) NASA (National Aeronautics and Space Administration) MDA (DOD Missile Defense Agency)	$96,259,350	1.1%	Rank history: #12 in FY2021, #20 in FY2022, #33 in FY2023 and #4 in FY2025; up 26 since FY2023.
8	Jones Lang Lasalle Americas, Inc. 2 awardees, including Advanced Technologies Group Inc. Top agencies GSA (General Services Administration) DECA (Defense Commissary Agency) AOUSC (Administrative Office of the U.S. Courts)	$89,765,471	1.0%	Rank history: not on the FY2021–FY2023 lists and #8 in FY2025; new.
9	Guidehouse Inc. Through Aptim Federal Services, LLC Top agencies DLA (Defense Logistics Agency)	$75,526,715	0.9%	Rank history: not on the FY2021–FY2023 lists and #60 in FY2025; new.
10	Pond Constructors Inc. Top agencies DLA (Defense Logistics Agency) Army (Department of the Army)	$72,886,153	0.9%	Rank history: #60 in FY2021, #22 in FY2022, #17 in FY2023 and #16 in FY2025; up 7 since FY2023.
11	Weston Solutions Holdings, Inc. 2 awardees, including Weston Solutions, Inc. Top agencies DLA (Defense Logistics Agency) Army (Department of the Army)	$71,773,991	0.8%	Rank history: #10 in FY2021, #11 in FY2022, #10 in FY2023 and #23 in FY2025; down 1 since FY2023.
12	Jacobs Government Services Company 3 awardees, including Amentum Technology, Inc. and Jacobs Engineering Group Inc. Top agencies NASA (National Aeronautics and Space Administration) GAO (Government Accountability Office)	$65,504,657	0.8%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
13	Tetra TECH Inc. 5 awardees, including Bluewater Federal Solutions, Inc. Top agencies DLA (Defense Logistics Agency) Army (Department of the Army) Navy (Department of the Navy)	$64,118,697	0.7%	Rank history: not on the FY2021 list, #46 in FY2022, #47 in FY2023 and #43 in FY2025; up 34 since FY2023.
14	Action Facilities Management Inc. 2 awardees, including Action Integrated Services LLC Top agencies GSA (General Services Administration) DOJ (Department of Justice) Army (Department of the Army)	$62,779,962	0.7%	Rank history: #46 in FY2021, #44 in FY2022, #21 in FY2023 and #9 in FY2025; up 7 since FY2023.
15	Professional Contract Services, Inc. Top agencies Navy (Department of the Navy) Army (Department of the Army) DHS (Department of Homeland Security)	$55,928,233	0.7%	Rank history: #17 in FY2021, #14 in FY2022, #20 in FY2023 and #17 in FY2025; up 5 since FY2023.
16	Nana Regional Corporation Inc. 3 awardees, including Akima Range Readiness Operations LLC, Jade Creek Construction LLC and Sava Workforce Solutions LLC Top agencies USAF (Department of the Air Force) DOJ (Department of Justice)	$54,263,218	0.6%	Rank history: not on the FY2021–FY2022 lists, #43 in FY2023 and #11 in FY2025; up 27 since FY2023.
17	24 Asset Management Corp Top agencies HUD (Department of Housing and Urban Development)	$51,045,736	0.6%	Rank history: not on the FY2021 list, #15 in FY2022, not on the FY2023 list and not on the FY2025 list; returned.
18	Tatitlek Corporation Through Tatitlek Technologies, LLC Top agencies DOS (Department of State)	$50,922,918	0.6%	Rank history: not on the FY2021–FY2022 lists, #39 in FY2023 and #24 in FY2025; up 21 since FY2023.
19	Fluor Corporation Through Fluor Intercontinental, Inc. Top agencies USAF (Department of the Air Force)	$50,000,000	0.6%	Rank history: not on the FY2021–FY2023 lists and #18 in FY2025; new.
20	Amentum Holdings, Inc. 6 awardees, including Central Plateau Cleanup Company, LLC, Amentum Services, Inc. and Amentum Design and Facility Management Top agencies DOE (Department of Energy) Navy (Department of the Navy) NASA (National Aeronautics and Space Administration)	$48,921,232	0.6%	Rank history: not on the FY2021–FY2023 lists and #1 in FY2025; new.
21	Blueway One JV LLC Top agencies VA (Department of Veterans Affairs)	$48,788,000	0.6%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
22	Emcor Group Inc. 2 awardees, including Emcor Government Services, Inc. and Mesa Energy Systems, Inc. Top agencies GSA (General Services Administration) GAO (Government Accountability Office) HHS (Department of Health and Human Services)	$45,357,979	0.5%	Rank history: #5 in FY2021, #8 in FY2022, #13 in FY2023 and #25 in FY2025; down 9 since FY2023.
23	Four Seasons Environmental Inc. Top agencies HHS (Department of Health and Human Services) GSA (General Services Administration) USDA (Department of Agriculture)	$43,742,489	0.5%	Rank history: not on the FY2021–FY2022 lists, #77 in FY2023 and not on the FY2025 list; up 54 since FY2023.
24	Cottrell Contracting Corporation Top agencies Army (Department of the Army)	$42,643,077	0.5%	Rank history: #66 in FY2021, not on the FY2022 list, #93 in FY2023 and #20 in FY2025; up 69 since FY2023.
25	Nelson Refrigeration Inc. Top agencies DECA (Defense Commissary Agency)	$42,623,712	0.5%	Rank history: not on the FY2021–FY2023 lists and #14 in FY2025; new.
26	Waterfront Property Services, LLC Top agencies Army (Department of the Army)	$42,381,690	0.5%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 157 since FY2023.
27	Walsh Federal LLC Top agencies DOT (Department of Transportation)	$41,478,370	0.5%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
28	South Dade Air Conditioning & Refrigeration Inc. Top agencies GSA (General Services Administration) DHS (Department of Homeland Security) DOJ (Department of Justice)	$40,206,341	0.5%	Rank history: not on the FY2021 list, #64 in FY2022, #40 in FY2023 and #22 in FY2025; up 12 since FY2023.
29	Grunley Construction Co., Inc. Top agencies Navy (Department of the Navy)	$38,469,764	0.4%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
30	Valiant Integrated Services LLC 2 awardees, including Valiant Government Services LLC and Valiant / Alca JV LLC Top agencies Army (Department of the Army) DHA (Defense Health Agency) Navy (Department of the Navy)	$38,137,716	0.4%	Rank history: not on the FY2021–FY2022 lists, #34 in FY2023 and #39 in FY2025; up 4 since FY2023.
31	Jacobs Engineering Group Inc. 3 awardees, including Amentum Technology, Inc. Top agencies Navy (Department of the Navy) NASA (National Aeronautics and Space Administration)	$36,495,005	0.4%	Rank history: #2 in FY2021, #3 in FY2022, #4 in FY2023 and not on the FY2025 list; down 27 since FY2023.
32	Rbvetco, LLC Top agencies VA (Department of Veterans Affairs)	$36,052,109	0.4%	Rank history: not on the FY2021–FY2022 lists, #52 in FY2023 and not on the FY2025 list; up 20 since FY2023.
33	Serviam Construction LLC Top agencies VA (Department of Veterans Affairs)	$35,477,429	0.4%	Rank history: not on the FY2021–FY2023 lists and #29 in FY2025; up 437 since FY2023.
34	Kgjj Engineering Solutions, LLC Top agencies DHA (Defense Health Agency) Navy (Department of the Navy)	$34,545,844	0.4%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 124 since FY2023.
35	Manson Construction Co 2 awardees Top agencies Army (Department of the Army)	$33,610,991	0.4%	Rank history: #25 in FY2021, #26 in FY2022, #37 in FY2023 and #48 in FY2025; up 2 since FY2023.
36	Akima Facilities Operations LLC Top agencies Army (Department of the Army) USDA (Department of Agriculture)	$33,128,569	0.4%	Rank history: not on the FY2021–FY2023 lists and #21 in FY2025; up 424 since FY2023.
37	Aed, Inc. Through AED Stratecon, LLC Top agencies DOS (Department of State)	$32,223,775	0.4%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 115 since FY2023.
38	J G M Property Group, Inc. Top agencies HUD (Department of Housing and Urban Development) Commerce (Department of Commerce)	$32,096,472	0.4%	Rank history: not on the FY2021 list, #30 in FY2022, not on the FY2023 list and not on the FY2025 list; returned.
39	Jll-Midnight Sun Ifms LLC Top agencies Navy (Department of the Navy) DHA (Defense Health Agency) Army (Department of the Army)	$31,354,012	0.4%	Rank history: #35 in FY2021, #31 in FY2022, #48 in FY2023 and #36 in FY2025; up 9 since FY2023.
40	Marinex Construction Inc. Top agencies Army (Department of the Army)	$30,593,968	0.4%	Rank history: #44 in FY2021, #29 in FY2022, #14 in FY2023 and #63 in FY2025; down 26 since FY2023.
41	VGS Infrastructure Services Inc. Top agencies DLA (Defense Logistics Agency) Army (Department of the Army)	$30,037,590	0.4%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
42	Skookum Educational Programs Top agencies DHS (Department of Homeland Security) Army (Department of the Army) Navy (Department of the Navy)	$29,514,633	0.3%	Rank history: #21 in FY2021, #23 in FY2022, #18 in FY2023 and #65 in FY2025; down 24 since FY2023.
43	Yeajin E&C Co.,Ltd. Top agencies Army (Department of the Army) Navy (Department of the Navy)	$28,796,404	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
44	Cashman Dredging and Marine Contracting Co. LLC Top agencies Army (Department of the Army)	$28,446,184	0.3%	Rank history: not on the FY2021 list, #24 in FY2022, #30 in FY2023 and not on the FY2025 list; down 14 since FY2023.
45	Richard E Pierson Construction Co Inc. Top agencies Army (Department of the Army)	$28,414,195	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
46	Aptim Federal Services LLC Top agencies DLA (Defense Logistics Agency) Army (Department of the Army)	$28,223,949	0.3%	Rank history: #30 in FY2021, #10 in FY2022, #8 in FY2023 and not on the FY2025 list; down 38 since FY2023.
47	Bristol Bay Native Corporation 5 awardees, including Bristol General Contractors, LLC, Specpro Environmental Services LLC and CCI Facility Support Services, LLC Top agencies USAF (Department of the Air Force) DLA (Defense Logistics Agency) DHS (Department of Homeland Security)	$27,729,251	0.3%	Rank history: #64 in FY2021, #62 in FY2022, #75 in FY2023 and #31 in FY2025; up 28 since FY2023.
48	Chugach Alaska Corporation 4 awardees, including Wolf Creek Federal Services LLC, Chugach Consolidated Solutions, LLC and Chugach Solutions Enterprise, LLC Top agencies Army (Department of the Army) Navy (Department of the Navy) DTRA (Defense Threat Reduction Agency)	$26,504,203	0.3%	Rank history: #18 in FY2021, #16 in FY2022, #19 in FY2023 and not on the FY2025 list; down 29 since FY2023.
49	Kekolu-Rio Vista Joint Venture, LLC Top agencies Army (Department of the Army)	$25,804,958	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
50	Sedona- Nasco Joint Venture Top agencies Army (Department of the Army)	$25,248,747	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 90 since FY2023.
51	E Corp Top agencies DOT (Department of Transportation) USAF (Department of the Air Force)	$25,200,193	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 92 since FY2023.
52	Global Pacific Design Builders, LLC Top agencies Navy (Department of the Navy)	$25,132,607	0.3%	Rank history: not on the FY2021 list, #51 in FY2022, #16 in FY2023 and #33 in FY2025; down 36 since FY2023.
53	Ironclad Services Inc Top agencies VA (Department of Veterans Affairs) DOJ (Department of Justice) GSA (General Services Administration)	$24,864,204	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 256 since FY2023.
54	King & George, LLC 2 awardees, including Invicta Global, LLC Top agencies GSA (General Services Administration) Navy (Department of the Navy) Army (Department of the Army)	$24,604,589	0.3%	Rank history: #48 in FY2021, #37 in FY2022, #64 in FY2023 and #35 in FY2025; up 10 since FY2023.
55	Western Marine Construction, Inc. Top agencies Army (Department of the Army)	$24,563,000	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
56	Akima Range Readiness Operations LLC Top agencies USAF (Department of the Air Force)	$23,511,653	0.3%	Rank history: not on the FY2021–FY2022 lists, #26 in FY2023 and not on the FY2025 list; down 30 since FY2023.
57	Amentum Technology, Inc. Top agencies Navy (Department of the Navy)	$23,508,079	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
58	Georgia TECH Applied Research Corp Top agencies USAF (Department of the Air Force)	$23,195,884	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
59	SES Electrical LLC Top agencies DHA (Defense Health Agency)	$23,109,661	0.3%	Rank history: not on the FY2021–FY2022 lists, #95 in FY2023 and not on the FY2025 list; up 36 since FY2023.
60	Krima Construction Corp. Top agencies USAF (Department of the Air Force) Army (Department of the Army)	$22,583,829	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 167 since FY2023.
61	DB Netz AG Regionalnetz Oberpfalz Top agencies Army (Department of the Army)	$22,341,045	0.3%	Rank history: not on the FY2021 list, #57 in FY2022, #55 in FY2023 and #94 in FY2025; down 6 since FY2023.
62	Orion Marine Construction, Inc. Top agencies Army (Department of the Army)	$22,313,549	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
63	Norfolk Dredging Company Top agencies Army (Department of the Army) Navy (Department of the Navy)	$22,294,498	0.3%	Rank history: #9 in FY2021, #12 in FY2022, #7 in FY2023 and #10 in FY2025; down 56 since FY2023.
64	Curtin Maritime Corp Top agencies Army (Department of the Army)	$22,232,395	0.3%	Rank history: not on the FY2021 list, #41 in FY2022, #23 in FY2023 and #6 in FY2025; down 41 since FY2023.
65	Nve, Inc. Top agencies USDA (Department of Agriculture) Treasury (Department of the Treasury) USAF (Department of the Air Force)	$21,978,602	0.3%	Rank history: not on the FY2021–FY2023 lists and #68 in FY2025; up 45 since FY2023.
66	Hamilton Pacific Chamberlain LLC Top agencies VA (Department of Veterans Affairs) DOI (Department of the Interior) USDA (Department of Agriculture)	$21,753,356	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 247 since FY2023.
67	Yang Enterprises, Inc. Top agencies USAF (Department of the Air Force)	$21,541,155	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
68	HME Construction Inc. Top agencies Army (Department of the Army) DHS (Department of Homeland Security)	$21,491,493	0.3%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
69	Northern Management Services, Inc. Top agencies GSA (General Services Administration) DOI (Department of the Interior) DOJ (Department of Justice)	$21,421,427	0.3%	Rank history: not on the FY2021 list, #83 in FY2022, #60 in FY2023 and #61 in FY2025; down 9 since FY2023.
70	American Engineering Corporation Top agencies Navy (Department of the Navy) DLA (Defense Logistics Agency) DODEA (Department of Defense Education Activity)	$20,361,902	0.2%	Rank history: not on the FY2021–FY2023 lists and #67 in FY2025; new.
71	Louis Berger U.S. Inc. 3 awardees, including VGS Infrastructure Services Inc. and VGS Aircraft Services, Inc. Top agencies DLA (Defense Logistics Agency) Army (Department of the Army) Navy (Department of the Navy)	$20,082,149	0.2%	Rank history: #68 in FY2021, #40 in FY2022, #35 in FY2023 and not on the FY2025 list; down 36 since FY2023.
72	Yukon Fire Protection Services Inc. Top agencies GSA (General Services Administration) SSA (Social Security Administration) AOUSC (Administrative Office of the U.S. Courts)	$20,070,642	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 110 since FY2023.
73	Vectrus Systems Corporation Through V2X Systems LLC Top agencies Navy (Department of the Navy) Army (Department of the Army)	$20,005,868	0.2%	Rank history: #31 in FY2021, #19 in FY2022, #32 in FY2023 and not on the FY2025 list; down 41 since FY2023.
74	Pundir Group, Inc. Top agencies GSA (General Services Administration) AOUSC (Administrative Office of the U.S. Courts) HHS (Department of Health and Human Services)	$19,736,422	0.2%	Rank history: not on the FY2021–FY2023 lists and #50 in FY2025; up 67 since FY2023.
75	Abhe & Svoboda, Inc. Top agencies Army (Department of the Army)	$19,474,792	0.2%	Rank history: not on the FY2021–FY2022 lists, #50 in FY2023 and not on the FY2025 list; down 25 since FY2023.
76	Tactical Infrastructure Maintenance Solutions LLC Top agencies DHS (Department of Homeland Security)	$19,337,521	0.2%	Rank history: #59 in FY2021, #70 in FY2022, #94 in FY2023 and #64 in FY2025; up 18 since FY2023.
77	Royce Construction Services, LLC Top agencies DHA (Defense Health Agency) Army (Department of the Army) USAF (Department of the Air Force)	$19,327,508	0.2%	Rank history: #63 in FY2021, #71 in FY2022, #56 in FY2023 and not on the FY2025 list; down 21 since FY2023.
78	LB & B Associates Inc. Top agencies GSA (General Services Administration) AOUSC (Administrative Office of the U.S. Courts) DOJ (Department of Justice)	$19,221,243	0.2%	Rank history: not on the FY2021 list, #77 in FY2022, #99 in FY2023 and #58 in FY2025; up 21 since FY2023.
79	Southern Dredging Co Inc. Top agencies Army (Department of the Army)	$19,148,747	0.2%	Rank history: not on the FY2021 list, #63 in FY2022, not on the FY2023 list and not on the FY2025 list; up 203 since FY2023.
80	Valiant Construction LLC Top agencies VA (Department of Veterans Affairs)	$18,718,544	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
81	Spectrum Solutions Acquisitions, LLC Top agencies HUD (Department of Housing and Urban Development)	$18,704,183	0.2%	Rank history: not on the FY2021 list, #68 in FY2022, not on the FY2023 list and not on the FY2025 list; returned.
82	Tyonek Aircraft Overhaul, LLC Top agencies DHS (Department of Homeland Security)	$18,387,932	0.2%	Rank history: not on the FY2021–FY2022 lists, #51 in FY2023 and not on the FY2025 list; down 31 since FY2023.
83	Elektro-Krueck-Gmbh, Elektroinstallationen Top agencies Army (Department of the Army)	$18,199,989	0.2%	Rank history: #83 in FY2021, not on the FY2022–FY2023 lists and #52 in FY2025; returned.
84	R-Con Construction Inc. Top agencies USAF (Department of the Air Force)	$18,144,763	0.2%	Rank history: not on the FY2021 list, #43 in FY2022, not on the FY2023 list and not on the FY2025 list; up 172 since FY2023.
85	Koman Construction, LLC Top agencies DHS (Department of Homeland Security) DLA (Defense Logistics Agency)	$17,987,701	0.2%	Rank history: not on the FY2021 list, #95 in FY2022, not on the FY2023 list and #45 in FY2025; returned.
86	Birmingham Industrial Construction, LLC Top agencies VA (Department of Veterans Affairs) USAF (Department of the Air Force)	$17,906,794	0.2%	Rank history: not on the FY2021–FY2023 lists and #38 in FY2025; up 118 since FY2023.
87	The Dutra Group Top agencies Army (Department of the Army)	$17,739,404	0.2%	Rank history: #7 in FY2021, not on the FY2022 list, #31 in FY2023 and #30 in FY2025; down 56 since FY2023.
88	Qcm, Inc. Top agencies WHS (DOD Washington Headquarters Service) DOI (Department of the Interior) Commerce (Department of Commerce)	$17,379,670	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 60 since FY2023.
89	Olgoonik Enterprises, LLC Top agencies Commerce (Department of Commerce) GSA (General Services Administration) USAF (Department of the Air Force)	$17,328,633	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 49 since FY2023.
90	Reasor Building Group LLC Top agencies Army (Department of the Army) USAF (Department of the Air Force) Navy (Department of the Navy)	$17,251,238	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 95 since FY2023.
91	Iron Sword Enterprises, LLC Top agencies VA (Department of Veterans Affairs) Army (Department of the Army)	$17,104,401	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
92	Mcmillen, Inc. Top agencies Army (Department of the Army)	$17,029,928	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
93	MDM Construction LLC Top agencies VA (Department of Veterans Affairs)	$16,736,737	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 356 since FY2023.
94	Civil Works Contracting LLC Top agencies Navy (Department of the Navy)	$16,734,472	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; up 266 since FY2023.
95	Government Contracting Resources, Inc. Top agencies Navy (Department of the Navy) DLA (Defense Logistics Agency) USAF (Department of the Air Force)	$16,373,733	0.2%	Rank history: not on the FY2021–FY2023 lists and #98 in FY2025; up 22 since FY2023.
96	J&J and Alms Mission Support Solutions, LLC Top agencies Navy (Department of the Navy) USAF (Department of the Air Force)	$16,220,259	0.2%	Rank history: not on the FY2021–FY2023 lists and #32 in FY2025; new.
97	Genesis 360 LLC Top agencies Army (Department of the Army)	$16,132,978	0.2%	Rank history: not on the FY2021–FY2023 lists and not on the FY2025 list; new.
98	Fedcap Rehabilitation Services, Inc. Top agencies GSA (General Services Administration) AOUSC (Administrative Office of the U.S. Courts) DOJ (Department of Justice)	$16,127,435	0.2%	Rank history: not on the FY2021–FY2022 lists, #73 in FY2023 and #55 in FY2025; down 25 since FY2023.
99	DAE Sung LLC Top agencies GSA (General Services Administration) AOUSC (Administrative Office of the U.S. Courts) DHS (Department of Homeland Security)	$16,119,071	0.2%	Rank history: not on the FY2021–FY2023 lists and #100 in FY2025; up 71 since FY2023.
100	Electronic Metrology Laboratory, LLC Top agencies GSA (General Services Administration) Treasury (Department of the Treasury) DOJ (Department of Justice)	$15,843,734	0.2%	Rank history: not on the FY2021–FY2023 lists and #62 in FY2025; up 69 since FY2023.

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100 of 3,606 contractors listed here. See the rest on GovTribe.

Rankings for the codes under PSC Z1

Code	Net obligations	Largest contractor
Z1AA Maintenance of Office Buildings	$1,109,171,870	Jones Lang Lasalle Americas, Inc.
Z1DA Maintenance of Hospitals and Infirmaries	$981,995,493	J & J Maintenance Inc.
Z1JZ Maintenance of Miscellaneous Buildings	$847,119,479	J & J Maintenance Inc.
Z1KF Maintenance of Dredging Facilities	$836,053,544	Great Lakes Dredge & Dock Corporation
Z1AZ Maintenance of Other Administrative Facilities and Service Buildings	$566,879,152	Arctic Slope Regional Corporation
Z1NA Maintenance of Fuel Supply Facilities	$413,045,667	Guidehouse Inc.
Z1KB Maintenance of Canals	$356,283,563	Great Lakes Dredge & Dock Corporation
Z1PZ Maintenance of Other Non-Building Facilities	$289,733,496	Jacobs Engineering Group Inc.
Z1LB Maintenance of Highways/Roads/Streets/Bridges/Railways	$262,231,735	Kekolu-Rio Vista Joint Venture, LLC
Z1HB Maintenance of Government-Owned Government-Operated (Gogo) R&D Facilities	$172,258,361	General Dynamics Corporation
Z1QA Maintenance of Restoration of Real Property (Public or Private)	$138,472,055	Nana Regional Corporation Inc.
Z1KA Maintenance of Dams	$111,759,794	Mcmillen, Inc.
Z1BD Maintenance of Airport Runways and Taxiways	$107,145,532	Fluor Corporation
Z1FC Maintenance of Troop Housing Facilities	$95,101,508	Bristol Bay Native Corporation
Z1EB Maintenance of Maintenance Buildings	$94,887,542	Allied Pacific Builders Inc
Z1BA Maintenance of Air Traffic Control Towers	$94,279,485	Walsh Federal LLC
Z1FA Maintenance of Family Housing Facilities	$83,943,712	Global Pacific Design Builders, LLC
Z1DB Maintenance of Laboratories and Clinics	$78,292,620	Valiant Integrated Services LLC
Z1NB Maintenance of Heating and Cooling Plants	$70,915,863	Performanceepc-Greenland JV LLC
Z1BZ Maintenance of Other Airfield Structures	$62,184,203	Grunley Construction Co., Inc.
Z1CA Maintenance of Schools	$58,495,837	SKE Technical Services GMBH
Z1BC Maintenance of Radar and Navigational Facilities	$58,072,195	Georgia TECH Applied Research Corp
Z1BG Maintenance of Electronic and Communications Facilities	$47,393,530	Silver Lake Construction LLC
Z1DZ Maintenance of Other Hospital Buildings	$37,319,077	Capex Construction LLC
Z1FB Maintenance of Recreational Buildings	$36,791,287	Pacific Design Builders, LLC
Z1EZ Maintenance of Other Industrial Buildings	$36,390,484	Military & Federal Construction Co., Inc.
Z1LZ Maintenance of Parking Facilities	$30,687,085	North State Mechanical Inc.
Z1NE Maintenance of Water Supply Facilities	$28,192,518	Ahtna Builders, LLC
Z1NZ Maintenance of Other Utilities	$25,965,631	CCI Facility Support Services, LLC
Z1PA Maintenance of Recreation Facilities (Non-Building)	$19,507,745	Kompan GMBH
Z1GZ Maintenance of Other Warehouse Buildings	$19,345,212	Integriward LLC
Z1ND Maintenance of Sewage and Waste Facilities	$17,342,602	Nikken Sogyo Co., Ltd.
Z1JA Maintenance of Museums and Exhibition Buildings	$16,537,172	Huang-Cfm Joint Venture
Z1PC Maintenance of Unimproved Real Property (Land)	$16,276,036	Ground Level Construction Inc.
Z1AB Maintenance of Conference Space and Facilities	$8,780,377	Krima Construction Corp.
Z1FZ Maintenance of Other Residential Buildings	-$17,139,082	24 Asset Management Corp

Show all 36

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 $8.56 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. 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 2024 ran Oct 1, 2023 – Sep 30, 2024. 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 FY2023. "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 FY2023 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

Who were the top 10 PSC Z1 contractors in FY2024?

1. Great Lakes Dredge & Dock Corporation ($516M), 2. Amentum Services, Inc. ($497M), 3. J & J Maintenance Inc. ($241M), 4. Peter Kiewit Sons', Inc. ($163M), 5. General Dynamics Corporation ($103M), 6. Facility Services Management, Inc. ($99.1M), 7. Arctic Slope Regional Corporation ($96.3M), 8. Jones Lang Lasalle Americas, Inc. ($89.8M), 9. Guidehouse Inc. ($75.5M), 10. Pond Constructors Inc. ($72.9M).

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