Company lists · Data refreshed September 2026

Top 25 Infrastructure law firms based in Washington, United States

Name: Infrastructure law firms based in Washington, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 134 companies tracked

RevenueBase identified 134 infrastructure law firms headquartered in Washington, United States as of September 2026 and tracks 16,036 professional contacts across them, including 9,721 with verified work emails. Houston is the largest hub.

This list covers infrastructure law firms headquartered in Washington, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 21, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 21, 2026 86% judged on-target in blind review

134Companies

16,036Contacts tracked

9,721Verified emails

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The 25 largest infrastructure law firms based in Washington, United States

Ranked by team size

Top 25 of 134 infrastructure law firms based in Washington, United States, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to infrastructure law firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Arnold & Porter	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,333 contacts →
	Indirect evidence “Arnold & Porter combines sophisticated regulatory, litigation, and transactional capabilities to resolve clients’ most complex issues.” Source: RevenueBase Database · checked Sep 21, 2026
2	Venable LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,790 contacts →
	Partial evidence “Committed to Your Success – As a law firm of more than 900 professionals, Venable delivers legal services globally in every area of regulatory compliance, government affairs…” Source: RevenueBase Database · checked Sep 21, 2026
3	Crowell & Moring	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,602 contacts →
	Partial evidence “Crowell & Moring is an international law firm with operations in the United States, Europe, MENA, and Asia.” Source: RevenueBase Database · checked Sep 21, 2026
4	Wiley Rein LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	501-1,000	576 contacts →
	Indirect evidence “Founded in 1983, Wiley is a dominant presence in the nation’s capital.” Source: RevenueBase Database · checked Sep 21, 2026
5	Synergy Consulting, INC	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	434 contacts →
	Indirect evidence “Synergy Consulting is Global Leader in Financial and Corporate Advisory.” Source: RevenueBase Database · checked Sep 21, 2026
6	Beveridge & Diamond PC	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	201-500	328 contacts →
	Indirect evidence “Beveridge & Diamond’s 170+ lawyers in 7 U.S.” Source: RevenueBase Database · checked Sep 21, 2026
7	Keller And Heckman LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	230 contacts →
	Partial evidence “Keller and Heckman, founded in 1962, has a broad practice in the areas of regulatory law, public policy, and litigation, serving both domestic and international clients.” Source: RevenueBase Database · checked Sep 21, 2026
8	Mckissack & Mckissack	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	175 contacts →
	Indirect evidence “McKissack & McKissack is a national architectural, engineering, program and construction management firm with 30 years of experience working with clients to envision and deliver…” Source: RevenueBase Database · checked Sep 21, 2026
9	VAN Ness Feldman LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	174 contacts →
	Partial evidence “Van Ness Feldman is a nationally recognized mid-sized law firm specializing in the areas of energy, environment, and natural resources law and policy, with offices in Washington…” Source: RevenueBase Database · checked Sep 21, 2026
10	Astris Finance, LLC	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	74 contacts →
	Partial evidence “Founded in Astris Finance, a Colliers company, is an independent financial advisory firm specialized in the Infrastructure and Energy (I&E) sectors with an exceptional track…” Source: RevenueBase Database · checked Sep 21, 2026
11	Reno & Cavanaugh, Pllc	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	73 contacts →
	Partial evidence “Since 1977, Reno & Cavanaugh has been a national law firm dedicated to strengthening communities through strategic use of public and private resources.” Source: RevenueBase Database · checked Sep 21, 2026
12	DOW Lohnes	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	201-500	73 contacts →
	Indirect evidence “On January 1, 2014, Dow Lohnes merged with Cooley LLP.” Source: RevenueBase Database · checked Sep 21, 2026
13	Pilieromazza Pllc	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	70 contacts →
	Partial evidence “PilieroMazza – a business law firm – serves as a strategic partner to government contractors and commercial businesses from across the United States in numerous industries.” Source: RevenueBase Database · checked Sep 21, 2026
14	HWG LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	70 contacts →
	Partial evidence “HWG LLP is a boutique law firm designed to offer clients access to top tier legal talent without unnecessary overhead.” Source: RevenueBase Database · checked Sep 21, 2026
15	Lewis Baach Kaufmann Middlemiss Pllc	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	11-50	64 contacts →
	Indirect evidence “Lewis Baach Kaufmann Middlemiss is a premier international firm with extensive practices in insurance, reinsurance, international financial disputes and global commercial…” Source: RevenueBase Database · checked Sep 21, 2026
16	Hayat Brown LLC	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	51-200	50 contacts →
	Partial evidence “Comprised of experienced, savvy professionals, Hayat Brown provides services in engineering and P3, real estate and infrastructure advisory.” Source: RevenueBase Database · checked Sep 21, 2026
17	Conn Maciel Carey LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	11-50	46 contacts →
	Partial evidence “Conn Maciel Carey LLP is a boutique law firm focused on Labor & Employment, Workplace Safety - OSHA/MSHA, and Litigation.” Source: RevenueBase Database · checked Sep 21, 2026
18	John & Hengerer LLP	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	n/a	46 contacts →
	Indirect evidence “John & Hengerer LLP represents and advises energy companies, inlcuding natural gas producers, importers, processors, and marketers; gas and liquids pipeline operators; gas storage…” Source: RevenueBase Database · checked Sep 21, 2026
19	Peacock Keller, LLP	Partial evidence	Washington, PA, United StatesHQ checked Sep 21, 2026	51-200	38 contacts →
	Partial evidence “Peacock Keller is a full service law firm headquartered in Washington, Pennsylvania.” Source: RevenueBase Database · checked Sep 21, 2026
20	Tiber Hudson LLC	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	11-50	36 contacts →
	Partial evidence “Tiber Hudson LLC is a boutique law firm focused in providing legal services including complex commercial litigation, complex commercial transactions, corporate structure and…” Source: RevenueBase Database · checked Sep 21, 2026
21	Spiegel & Mcdiarmid LLP	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	11-50	29 contacts →
	Partial evidence “Spiegel & McDiarmid LLP was formed to represent the public side of our nation’s critical infrastructure industries, including energy, telecommunications and transportation.” Source: RevenueBase Database · checked Sep 21, 2026
22	Picard Kentz & Rowe LLP	Partial evidence	Washington, United StatesHQ checked Sep 21, 2026	11-50	28 contacts →
	Partial evidence “Picard Kentz & Rowe is a firm expert in international law, international litigation and arbitration, international trade and investment, and advocacy on behalf of clients…” Source: RevenueBase Database · checked Sep 21, 2026
23	Duncan, Weinberg, Genzer & Pembroke, P.C. Dwgp	Indirect evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	11-50	28 contacts →
	Indirect evidence “Since its founding in 1971, DWG & P, has provided a broad range of counseling, regulatory, litigation and legislative services to clients in every region of the country.” Source: RevenueBase Database · checked Sep 21, 2026
24	Interagency INC	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	11-50	19 contacts →
	Partial evidence “InterAgency provides preconstruction consulting for the Washington Metro Area’s most complex and challenging infrastructure projects.” Source: RevenueBase Database · checked Sep 21, 2026
25	Amis Patel Brewer	Partial evidence	Washington, DC, United StatesHQ checked Sep 21, 2026	1-10	18 contacts →
	Partial evidence “Amis, Patel & Brewer, LLP is a boutique law firm focused on providing legal services to the renewable energy and sustainability sectors.” Source: RevenueBase Database · checked Sep 21, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: infrastructure law firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names infrastructure law firms.
Partial evidence: Its own public description names part of infrastructure law firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name infrastructure law firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 134 infrastructure law firms based in Washington, United States

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Infrastructure law firms based in Washington, United States at a glance

As of Sep 21, 2026

60.6%Verified-email coverage

119.7Average contacts per company

1-10Median size (employees)

123.9%Largest-city concentration · Houston

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

Email recency for this list is measured across the whole United States list rather than for Washington, so it is reported there. Company counts and contact totals on this page are exact for Washington, over 134 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among infrastructure law firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in Washington, United States whose own description of what they do matches “infrastructure law firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names infrastructure law firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among infrastructure law firms, and records with no verified work email. Companies headquartered outside Washington are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 9,721 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 21, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Infrastructure law firms by metro in the United States

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names infrastructure law firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many infrastructure law firms are there based in Washington, United States?

RevenueBase identified 134 infrastructure law firms headquartered in Washington, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Arnold & Porter, headquartered in Washington, tops this list with the largest team on record.

Which city has the most infrastructure law firms?

Houston leads with 166 headquartered companies, followed by New York (162) and Washington (134).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 9,721 verified decision-maker contacts tracked across these 134 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 21, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.