Top 100 Contractors in NAICS 335311: Power, Distribution, and Specialty Transformer Manufacturing, FY2021

Name: Top 100 Contractors in NAICS 335311: Power, Distribution, and Specialty Transformer Manufacturing, FY2021
Creator: GovTribe

Parent companies by net contract obligations Oct 1, 2020 – Sep 30, 2021 Code page on GovTribe

The top 10 won 60% of FY2021 NAICS 335311 contract dollars

Contract obligations: $182,139,186 Net of deobligations, by contracts coded NAICS 335311
Contractors: 703 Parent companies with an obligation
Largest contractor: Tepco Energy Partner Incorporated $35.5 million, 18.9% 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	Tepco Energy Partner Incorporated Top agencies USAF (Department of the Air Force) Navy (Department of the Navy) Army (Department of the Army)	$35,515,191	18.9%	Rank history: #1 in FY2022, #1 in FY2023, #1 in FY2024 and #1 in FY2025; new, not ranked in FY2020.
2	RCT Systems, Inc. Top agencies Navy (Department of the Navy)	$16,160,511	8.6%	Rank history: not on the FY2022–FY2023 lists, #6 in FY2024 and #60 in FY2025; new, not ranked in FY2020.
3	Siemens Aktiengesellschaft 2 awardees, including Siemens Industry Inc. and Siemens Government Technologies Inc. Top agencies USAF (Department of the Air Force) DOS (Department of State)	$11,544,317	6.2%	Rank history: #7 in FY2022, #5 in FY2023, #7 in FY2024 and not on the FY2025 list; down 1 since FY2020.
4	Schneider Electric Buildings Americas Inc. Through Schneider Electric Usa, Inc. Top agencies DOT (Department of Transportation)	$10,684,275	5.7%	Rank history: #20 in FY2022 and not on the FY2023–FY2025 lists; unchanged since FY2020.
5	The Chugoku Electric Power Company, Incorporated Top agencies Navy (Department of the Navy)	$10,577,160	5.6%	Rank history: #2 in FY2022, #2 in FY2023, #3 in FY2024 and #3 in FY2025; new, not ranked in FY2020.
6	Evoqua Water Technologies LLC 2 awardees Top agencies Navy (Department of the Navy)	$8,446,633	4.5%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
7	Tohoku Electric Power Company Incorporated Top agencies USAF (Department of the Air Force)	$6,888,906	3.7%	Rank history: #3 in FY2022, #3 in FY2023, #4 in FY2024 and #6 in FY2025; new, not ranked in FY2020.
8	Interdyne Corp Top agencies Army (Department of the Army)	$4,421,662	2.4%	Rank history: not on the FY2022–FY2025 lists; down 2 since FY2020.
9	Jenoptik AG 2 awardees, including Vincorion LLC and Vincorion Power Systems GMBH Top agencies Army (Department of the Army)	$3,864,178	2.1%	Rank history: #16 in FY2022 and not on the FY2023–FY2025 lists; up 3 since FY2020.
10	G & RK Consulting Associates LLC Top agencies DOE (Department of Energy)	$3,649,033	1.9%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
11	Natel Engineering Company, LLC Top agencies Army (Department of the Army)	$2,689,506	1.4%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
12	RCT Holdings Inc. Through RCT Systems, Inc. Top agencies Navy (Department of the Navy)	$2,267,701	1.2%	Rank history: #5 in FY2022, #4 in FY2023 and not on the FY2024–FY2025 lists; down 2 since FY2020.
13	Jamaica Bearings Co., Inc. Top agencies DLA (Defense Logistics Agency)	$2,155,287	1.1%	Rank history: #13 in FY2022, #11 in FY2023, not on the FY2024 list and #18 in FY2025; up 23 since FY2020.
14	Board of Governers State University System of Florida Through Florida State University Top agencies Navy (Department of the Navy)	$1,929,618	1.0%	Rank history: #8 in FY2022, #26 in FY2023, #11 in FY2024 and not on the FY2025 list; new, not ranked in FY2020.
15	Ducommun Incorporated Through Ducommun Labarge Technologies, Inc. Top agencies Navy (Department of the Navy) DLA (Defense Logistics Agency)	$1,564,550	0.8%	Rank history: #18 in FY2022, #6 in FY2023 and not on the FY2024–FY2025 lists; up 6 since FY2020.
16	Hitachi, Ltd. Through Hitachi Energy USA Inc. Top agencies USAF (Department of the Air Force) Army (Department of the Army)	$1,562,573	0.8%	Rank history: not on the FY2022 list, #72 in FY2023 and not on the FY2024–FY2025 lists; new, not ranked in FY2020.
17	Crane Co Through Crane Electronics, Inc. Top agencies USAF (Department of the Air Force)	$1,475,903	0.8%	Rank history: not on the FY2022 list, #24 in FY2023, #61 in FY2024 and not on the FY2025 list; up 85 since FY2020.
18	Great Plains Communications LLC Through Strantech LLC Top agencies DISA (Defense Information Systems Agency) OPM (Office of Personnel Management)	$1,396,996	0.7%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
19	Leonardo S.p.A. 6 awardees, including DRS Network & Imaging Systems LLC, DRS Naval Power Systems Inc. and Laurel Technologies Partnership Top agencies Army (Department of the Army) Navy (Department of the Navy) DLA (Defense Logistics Agency)	$1,245,810	0.7%	Rank history: #4 in FY2022, #51 in FY2023, #10 in FY2024 and #5 in FY2025; unchanged since FY2020.
20	General Electric Company 3 awardees, including GE Aviation Systems LLC Top agencies Navy (Department of the Navy) Army (Department of the Army)	$1,198,032	0.6%	Rank history: #65 in FY2022, not on the FY2023 list, #75 in FY2024 and not on the FY2025 list; new, not ranked in FY2020.
21	Interconnect Wiring LLP Top agencies DLA (Defense Logistics Agency)	$1,194,111	0.6%	Rank history: #50 in FY2022, not on the FY2023–FY2024 lists and #73 in FY2025; up 5 since FY2020.
22	Teledyne Technologies Incorporated 2 awardees, including Teledyne Instruments Inc. Top agencies Navy (Department of the Navy)	$1,124,083	0.6%	Rank history: #6 in FY2022, #9 in FY2023, #8 in FY2024 and not on the FY2025 list; up 39 since FY2020.
23	Wireless Telecom Group, Inc. Through Boonton Electronics Corporation Top agencies Navy (Department of the Navy)	$1,123,508	0.6%	Rank history: #75 in FY2022, #71 in FY2023 and not on the FY2024–FY2025 lists; new, not ranked in FY2020.
24	L3Harris Technologies, Inc. 9 awardees, including L3Harris Maritime Power & Energy Solutions, Inc. and L3 Technologies, Inc. Top agencies Navy (Department of the Navy) DLA (Defense Logistics Agency)	$1,096,861	0.6%	Rank history: #15 in FY2022, #30 in FY2023, #32 in FY2024 and #4 in FY2025; down 23 since FY2020.
25	Bright Lights Usa, Inc. Top agencies Army (Department of the Army)	$1,093,409	0.6%	Rank history: #67 in FY2022, #34 in FY2023, #53 in FY2024 and not on the FY2025 list; up 394 since FY2020.
26	Ametek Inc. 3 awardees, including Ametek SCP Inc., Abaco Systems, Inc. and Powervar Inc. Top agencies Navy (Department of the Navy) VA (Department of Veterans Affairs)	$1,067,719	0.6%	Rank history: not on the FY2022 list, #27 in FY2023, not on the FY2024 list and #99 in FY2025; up 70 since FY2020.
27	The L.c.doane Company Top agencies DLA (Defense Logistics Agency)	$980,565	0.5%	Rank history: #73 in FY2022, #38 in FY2023, #62 in FY2024 and #72 in FY2025; up 14 since FY2020.
28	Export 220Volt Inc. Top agencies DOS (Department of State)	$898,640	0.5%	Rank history: #33 in FY2022 and not on the FY2023–FY2025 lists; new, not ranked in FY2020.
29	Space Vector, LLC Top agencies USAF (Department of the Air Force)	$882,090	0.5%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
30	MDF Technologies Inc. Top agencies DLA (Defense Logistics Agency) Navy (Department of the Navy)	$816,205	0.4%	Rank history: #49 in FY2022, #49 in FY2023, #81 in FY2024 and not on the FY2025 list; up 4 since FY2020.
31	Phillip Cable Manufacturing, Inc. Top agencies DLA (Defense Logistics Agency)	$767,932	0.4%	Rank history: #23 in FY2022, #16 in FY2023, #16 in FY2024 and #10 in FY2025; down 13 since FY2020.
32	Elemco Services, Inc. Top agencies VA (Department of Veterans Affairs)	$764,000	0.4%	Rank history: not on the FY2022 list, #44 in FY2023, #65 in FY2024 and #64 in FY2025; up 8 since FY2020.
33	Johnson Controls Security Solutions LLC Through Johnson Controls Navy Systems, LLC Top agencies DLA (Defense Logistics Agency)	$729,703	0.4%	Rank history: #24 in FY2022 and not on the FY2023–FY2025 lists; new, not ranked in FY2020.
34	Kampi Components Co Inc. Top agencies DLA (Defense Logistics Agency) Navy (Department of the Navy)	$719,827	0.4%	Rank history: #41 in FY2022, #36 in FY2023, #43 in FY2024 and #7 in FY2025; up 22 since FY2020.
35	MP Aero LLC Top agencies DLA (Defense Logistics Agency)	$675,420	0.4%	Rank history: not on the FY2022 list, #70 in FY2023 and not on the FY2024–FY2025 lists; up 53 since FY2020.
36	Homewood Sales Corporation Top agencies Navy (Department of the Navy)	$669,540	0.4%	Rank history: not on the FY2022–FY2025 lists; up 147 since FY2020.
37	General Dynamics Corporation 6 awardees, including Electric Boat Corporation, General Dynamics Land Systems Inc. and General Dynamics Land Systems - Canada Corporation Top agencies DLA (Defense Logistics Agency) Navy (Department of the Navy)	$656,417	0.3%	Rank history: #48 in FY2022, not on the FY2023–FY2024 lists and #8 in FY2025; up 82 since FY2020.
38	Coil Winding Specialist, Inc. Top agencies DHS (Department of Homeland Security) USAF (Department of the Air Force) DISA (Defense Information Systems Agency)	$637,272	0.3%	Rank history: #21 in FY2022, #22 in FY2023, #63 in FY2024 and #43 in FY2025; down 9 since FY2020.
39	Virginia Energy and Lighting, LLC Top agencies DISA (Defense Information Systems Agency)	$601,655	0.3%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
40	Dutch Valley Supply Co. Top agencies Navy (Department of the Navy)	$597,196	0.3%	Rank history: not on the FY2022–FY2025 lists; up 333 since FY2020.
41	ECI Defense Group, Inc. Top agencies DLA (Defense Logistics Agency) Navy (Department of the Navy)	$553,306	0.3%	Rank history: #51 in FY2022, #60 in FY2023, #80 in FY2024 and not on the FY2025 list; down 2 since FY2020.
42	Heale Manufacturing Co., Inc. Top agencies DLA (Defense Logistics Agency)	$508,260	0.3%	Rank history: not on the FY2022–FY2025 lists; up 241 since FY2020.
43	Triman Industries Inc. Top agencies DLA (Defense Logistics Agency) Navy (Department of the Navy)	$507,792	0.3%	Rank history: #47 in FY2022, #20 in FY2023, #35 in FY2024 and #31 in FY2025; down 19 since FY2020.
44	TNL Sales LLC Top agencies DLA (Defense Logistics Agency)	$484,090	0.3%	Rank history: not on the FY2022–FY2025 lists; up 7 since FY2020.
45	Midwest Electrical Construction Inc. Top agencies Navy (Department of the Navy)	$479,519	0.3%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
46	C E Niehoff & Co Top agencies DLA (Defense Logistics Agency)	$455,002	0.2%	Rank history: #35 in FY2022, #40 in FY2023, #59 in FY2024 and #58 in FY2025; down 23 since FY2020.
47	Jo-Kell Inc. Top agencies DLA (Defense Logistics Agency) Navy (Department of the Navy)	$448,173	0.2%	Rank history: #27 in FY2022, #23 in FY2023, #27 in FY2024 and #20 in FY2025; down 10 since FY2020.
48	Airborne Supply Inc. Top agencies DLA (Defense Logistics Agency)	$428,614	0.2%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
49	Microchip Technology Inc. Through Microsemi Frequency and Time Corp Top agencies Navy (Department of the Navy)	$396,160	0.2%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
50	Jag Components, LLC Top agencies DLA (Defense Logistics Agency)	$392,056	0.2%	Rank history: not on the FY2022–FY2025 lists; up 345 since FY2020.
51	Outdoor Venture Corp Through Ovc-Engineered Solutions LLC Top agencies DLA (Defense Logistics Agency)	$390,661	0.2%	Rank history: not on the FY2022–FY2025 lists; up 26 since FY2020.
52	U.s. Pan American Solutions LLC Top agencies Navy (Department of the Navy)	$384,293	0.2%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
53	Govage, Inc. Top agencies USAF (Department of the Air Force) Navy (Department of the Navy) Army (Department of the Army)	$376,046	0.2%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
54	Mary Helen Parkey Top agencies Navy (Department of the Navy) DOE (Department of Energy) Army (Department of the Army)	$371,100	0.2%	Rank history: #100 in FY2022, #31 in FY2023, #84 in FY2024 and #97 in FY2025; up 389 since FY2020.
55	Martin Military Inc. Top agencies DLA (Defense Logistics Agency)	$368,359	0.2%	Rank history: not on the FY2022–FY2025 lists; up 82 since FY2020.
56	Rock & Associates Top agencies DOE (Department of Energy)	$365,943	0.2%	Rank history: not on the FY2022–FY2025 lists; up 39 since FY2020.
57	ADI American Distributors, LLC 3 awardees, including Newvac, LLC and Microwave Components LLC Top agencies Navy (Department of the Navy) DLA (Defense Logistics Agency)	$352,587	0.2%	Rank history: #29 in FY2022, #52 in FY2023, #15 in FY2024 and not on the FY2025 list; up 46 since FY2020.
58	TE Connectivity Corporation 3 awardees, including Brantner and Associates, Inc. Top agencies DLA (Defense Logistics Agency)	$344,954	0.2%	Rank history: #64 in FY2022 and not on the FY2023–FY2025 lists; up 370 since FY2020.
59	Integrated Procurement Technologies Top agencies DLA (Defense Logistics Agency)	$334,432	0.2%	Rank history: #59 in FY2022 and not on the FY2023–FY2025 lists; down 24 since FY2020.
60	Adirondack Electronics Inc. Top agencies Navy (Department of the Navy) DLA (Defense Logistics Agency)	$334,165	0.2%	Rank history: #44 in FY2022 and not on the FY2023–FY2025 lists; up 37 since FY2020.
61	Aviate Enterprises, Inc. Top agencies VA (Department of Veterans Affairs) DLA (Defense Logistics Agency)	$330,516	0.2%	Rank history: not on the FY2022–FY2025 lists; up 157 since FY2020.
62	A. West Enterprise, LLC Top agencies USAF (Department of the Air Force)	$317,129	0.2%	Rank history: not on the FY2022–FY2025 lists; down 17 since FY2020.
63	Par Defense Industries, LLC Top agencies DLA (Defense Logistics Agency) Navy (Department of the Navy)	$312,234	0.2%	Rank history: #9 in FY2022, #19 in FY2023, #46 in FY2024 and #25 in FY2025; up 44 since FY2020.
64	Native American Transformer Services Inc. Top agencies Army (Department of the Army)	$312,082	0.2%	Rank history: #86 in FY2022 and not on the FY2023–FY2025 lists; down 37 since FY2020.
65	Pioneer Industries, LLC Top agencies DLA (Defense Logistics Agency)	$311,178	0.2%	Rank history: #45 in FY2022, #46 in FY2023, #24 in FY2024 and #44 in FY2025; up 13 since FY2020.
66	Powerstar Inc. Top agencies Navy (Department of the Navy)	$309,816	0.2%	Rank history: not on the FY2022–FY2025 lists; up 16 since FY2020.
67	R & M Government Services Inc. Top agencies DLA (Defense Logistics Agency) Army (Department of the Army)	$307,535	0.2%	Rank history: not on the FY2022 list, #64 in FY2023, #100 in FY2024 and not on the FY2025 list; up 65 since FY2020.
68	Transdigm Group Incorporated 4 awardees, including Semco Instruments, Inc., Tactair Fluid Controls Inc. and Janco Corporation Top agencies DLA (Defense Logistics Agency)	$304,628	0.2%	Rank history: #36 in FY2022, #45 in FY2023 and not on the FY2024–FY2025 lists; up 370 since FY2020.
69	Meggitt PLC Through Meggitt (Uk) Limited Top agencies Navy (Department of the Navy)	$297,278	0.2%	Rank history: not on the FY2022–FY2025 lists; down 21 since FY2020.
70	Oshkosh Corp 2 awardees, including Oshkosh Defense LLC and JLG Industries, Inc. Top agencies DLA (Defense Logistics Agency)	$296,535	0.2%	Rank history: #58 in FY2022, #58 in FY2023, #41 in FY2024 and #61 in FY2025; down 5 since FY2020.
71	Genesis JIT LLC Top agencies DLA (Defense Logistics Agency)	$291,429	0.2%	Rank history: #46 in FY2022 and not on the FY2023–FY2025 lists; down 33 since FY2020.
72	Cobham Advanced Electron Through Mission Systems Davenport Inc. Top agencies Navy (Department of the Navy)	$279,282	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
73	Aponte Power Services LLC Top agencies Army (Department of the Army)	$274,173	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
74	Blue Cord Logistic Strategies Inc. Top agencies DLA (Defense Logistics Agency)	$272,960	0.1%	Rank history: not on the FY2022–FY2025 lists; up 404 since FY2020.
75	Maddox Industrial Transformer, LLC Top agencies USAF (Department of the Air Force)	$272,845	0.1%	Rank history: not on the FY2022–FY2025 lists; up 220 since FY2020.
76	ACE Electronics of N.j., Inc. Top agencies DLA (Defense Logistics Agency)	$271,315	0.1%	Rank history: not on the FY2022–FY2025 lists; up 326 since FY2020.
77	PAF Electrical, Inc. Top agencies Army (Department of the Army)	$263,738	0.1%	Rank history: #32 in FY2022, #83 in FY2023, #34 in FY2024 and not on the FY2025 list; up 227 since FY2020.
78	RJY Group LLC Top agencies VA (Department of Veterans Affairs)	$262,867	0.1%	Rank history: #83 in FY2022 and not on the FY2023–FY2025 lists; down 11 since FY2020.
79	Ares Energy LP Top agencies DOJ (Department of Justice) DOS (Department of State)	$260,661	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
80	Aircraft Engineering & Installation Services, Inc. Top agencies DLA (Defense Logistics Agency)	$255,502	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
81	Thales Through Thales Defense & Security Inc. Top agencies DLA (Defense Logistics Agency)	$254,470	0.1%	Rank history: not on the FY2022–FY2025 lists; up 31 since FY2020.
82	GE Energy Power Conversion USA Inc. Top agencies Navy (Department of the Navy)	$249,500	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
83	Design Criteria, Inc. Top agencies USAF (Department of the Air Force)	$245,506	0.1%	Rank history: #25 in FY2022 and not on the FY2023–FY2025 lists; up 188 since FY2020.
84	Fairbanks Morse LLC Top agencies Navy (Department of the Navy)	$245,000	0.1%	Rank history: not on the FY2022 list, #56 in FY2023 and not on the FY2024–FY2025 lists; new, not ranked in FY2020.
85	Wright Source Inc. Top agencies DLA (Defense Logistics Agency)	$242,137	0.1%	Rank history: not on the FY2022–FY2023 lists, #71 in FY2024 and not on the FY2025 list; up 57 since FY2020.
86	Cortek Test Solutions, LLC Top agencies Navy (Department of the Navy)	$229,568	0.1%	Rank history: not on the FY2022–FY2025 lists; up 293 since FY2020.
87	Phoenix Trading Inc. Top agencies DLA (Defense Logistics Agency)	$228,947	0.1%	Rank history: not on the FY2022 list, #96 in FY2023 and not on the FY2024–FY2025 lists; down 6 since FY2020.
88	Washington Foundries Inc. Top agencies DLA (Defense Logistics Agency)	$228,134	0.1%	Rank history: not on the FY2022–FY2025 lists; up 255 since FY2020.
89	Global Logistics Strategies Inc. Top agencies DLA (Defense Logistics Agency)	$224,315	0.1%	Rank history: #98 in FY2022, #90 in FY2023 and not on the FY2024–FY2025 lists; up 5 since FY2020.
90	B & P Consort, Inc. Top agencies Army (Department of the Army) Navy (Department of the Navy)	$220,696	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
91	Science Applications International Corporation Through Asrc Federal Facilities Logistics, LLC Top agencies DLA (Defense Logistics Agency)	$220,657	0.1%	Rank history: #42 in FY2022, #62 in FY2023 and not on the FY2024–FY2025 lists; down 60 since FY2020.
92	Phds Co. Top agencies Navy (Department of the Navy)	$219,620	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
93	A F Technologies Inc. Top agencies DLA (Defense Logistics Agency)	$219,058	0.1%	Rank history: not on the FY2022–FY2025 lists; up 12 since FY2020.
94	Al Muamroon Trading Top agencies USAF (Department of the Air Force)	$218,517	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
95	Container Research Corp Top agencies Navy (Department of the Navy)	$214,202	0.1%	Rank history: not on the FY2022–FY2025 lists; new, not ranked in FY2020.
96	F & R Sales, Inc. Top agencies DLA (Defense Logistics Agency)	$208,939	0.1%	Rank history: not on the FY2022–FY2025 lists; down 30 since FY2020.
97	RTX Corporation 4 awardees, including Raytheon Company, Simmonds Precision Products Inc. and Kidde Technologies, Inc. Top agencies DLA (Defense Logistics Agency)	$208,298	0.1%	Rank history: not on the FY2022–FY2025 lists; down 50 since FY2020.
98	ULB LLC Top agencies Army (Department of the Army)	$202,810	0.1%	Rank history: not on the FY2022–FY2025 lists; up 296 since FY2020.
99	Unitron, LP Top agencies USAF (Department of the Air Force) Army (Department of the Army)	$201,863	0.1%	Rank history: not on the FY2022 list, #50 in FY2023 and not on the FY2024–FY2025 lists; up 139 since FY2020.
100	Federal Contracts LLC Top agencies Army (Department of the Army)	$201,460	0.1%	Rank history: not on the FY2022–FY2025 lists; up 52 since FY2020.

Show 75 more

100 of 703 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 $188 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 2021 ran Oct 1, 2020 – Sep 30, 2021. 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 FY2020. "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 FY2020 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 NAICS 335311 contractors in FY2021?

1. Tepco Energy Partner Incorporated ($35.5M), 2. RCT Systems, Inc. ($16.2M), 3. Siemens Aktiengesellschaft ($11.5M), 4. Schneider Electric Buildings Americas Inc. ($10.7M), 5. The Chugoku Electric Power Company, Incorporated ($10.6M), 6. Evoqua Water Technologies LLC ($8.45M), 7. Tohoku Electric Power Company Incorporated ($6.89M), 8. Interdyne Corp ($4.42M), 9. Jenoptik AG ($3.86M), 10. G & RK Consulting Associates LLC ($3.65M).

On GovTribe

Research every contractor on this list

Every contract, task order and IDV they hold
Their subsidiaries, teammates and competitors
Open opportunities they're positioned for
Alerts when they win new work

Try for free Login