What Hanley Flight & Zimmerman does

Hanley, Flight & Zimmerman, LLC (HFZ) is a Chicago-based intellectual property law firm founded in 2002 by three patent attorneys—Mark G. Hanley, James A. Flight, and Mark C. Zimmerman—who previously practiced together at a larger IP firm. The firm specializes exclusively in patent prosecution and pre-litigation IP consulting across electrical, software, mechanical, and biomedical technologies, serving Fortune 100/500 corporate IP departments and technology innovators. HFZ operates from a single office at 10 South Wacker Drive, Chicago, with a team of 50+ personnel (per the firm) and a deeper breakdown of 18 partners, 23 additional patent practitioners, and approximately 30 support staff per a 20-year retrospective.

HFZ's core service is patent prosecution, supported by a proprietary two-tier review process in which senior attorneys review all work from junior practitioners to ensure consistent, litigation-ready output. The firm has developed internal AI-based tools to support patent prosecution workflows, built by Capital Member Michael Lenisa (who holds patents on AI-related innovations), and practices a litigation-aware drafting methodology that assumes patents will be challenged. The firm's Patent Engineering Program creates a structured pipeline from Patent Engineer to Patent Agent to Associate to Capital Member, systematically converting engineering talent into patent attorneys. Ancillary services include trademark procurement and global portfolio management, freedom-to-operate analyses, portfolio assessments, non-infringement and invalidity opinions, and trial testimony. International filings are coordinated through a network of foreign patent counsel, with a dedicated International Filing Specialist on staff.

HFZ derives revenue entirely from professional services fees billed on an engagement-specific basis—primarily hourly rates for patent prosecution, with project-based fees for pre-litigation consulting, opinions, and trademark work. Pricing is not publicly disclosed. The firm represents six of the top 25 U.S. patent earning entities and, in 2024, 5 of the top 20 (per Harrity Patent 300 / AI Patent 100). Named enterprise clients include Ford, General Electric, Boeing, Texas Instruments, Emerson, Abbott Laboratories, John Deere, McAfee, VMware, Hewlett-Packard, Nielsen, InSitu, Kolcraft, and Rite-Hite. Distribution is partner-led through direct enterprise relationships, supplemented by thought leadership at IPO, INTA, ACC CLE, Maiwald, and GE Aerospace events; HFZ does not use resellers, marketplaces, or paid acquisition channels.

Name

Hanley Flight & Zimmerman

Legal name

Hanley, Flight & Zimmerman, LLC

Website

https://hfzlaw.com

Company type

Private

Founded year

2002

Operating status

Operating

Headcount range

101–250 employees

Short description

Hanley Flight & Zimmerman is a Chicago-based patent prosecution and IP consulting law firm serving Fortune 100/500 corporate IP departments with engineer-attorneys specializing in electrical, software, mechanical, and biomedical technologies, operating with 50+ personnel from a single Chicago office.

Ownership category

akta.pro rank

Product category

Intellectual Property Law Services

NAICS

Legal Services (5411)

SIC

Services-Legal Services (8111)

akta.pro primary industry

Patent Prosecution & Portfolio Management (BPAHAMAA)

Keywords

• Patent prosecution services
• Patent portfolio management
• Intellectual property law
• Patent application drafting
• Trademark registration services

Headquarters

HQ city

Chicago

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Revenue model

1. Patent prosecution services: Hourly/engagement-based professional services for drafting and prosecuting U.S. and foreign patent applications in electrical, software, mechanical, and biomedical technologies. Primary revenue driver of the firm.
2. Patent project and litigation support services: Pre-litigation consulting, portfolio analysis, product clearance (freedom-to-operate) analyses, non-infringement and invalidity opinions, trial testimony and opinion work. Often delivered as discrete projects outside of ongoing prosecution relationships.
3. Trademark procurement and portfolio management: Federal trademark registration procurement and management of global trademark portfolios, including opposition and cancellation proceedings, licensing agreement drafting and negotiation, and copyright counseling.

Pricing tiers

Go-to-market motion3 records

Distribution channels3 records

Marketing channels5 records

Core offering

Hanley, Flight & Zimmerman, LLC (HFZ) is a Chicago-based patent consulting and prosecution law firm that drafts and prosecutes U.S. and foreign patent applications for clients in the electrical, software, mechanical, and biomedical arts. The firm also provides pre-litigation consulting, portfolio analysis, freedom-to-operate (product clearance) opinions, non-infringement and invalidity opinions, trial testimony, and global trademark procurement and portfolio management for large corporate clients.

Product overview

HFZ (Hanley, Flight & Zimmerman, LLC) is a Chicago-based patent prosecution and consulting law firm rather than a packaged software product. Its offering is organized as a core patent practice organized around four practice groups — Electrical & Software, Mechanical, Biomedical — that deliver the firm's two principal service lines: Patent Prosecution Services (the flagship, full-lifecycle drafting and prosecution of U.S. and foreign patent applications) and Patent Project Services (pre-litigation consulting, portfolio analysis, product clearance, opinion work, and trial testimony). Underpinning the practice is the Patent Engineering Program mentorship track that channels engineering talent into patent prosecution careers. Adjacent offerings include Trademark Services for federal and global trademark portfolio management and a Client Portal (a WordPress-based login system powered by LoginPress) for secure client access. Recognitions such as IAM Patent 1000, Chambers Spotlight, IAM Strategy 300 Global Leaders, and Harrity Patent 300 listings reflect the firm's standing among the top U.S. patent prosecution firms.

Differentiator

Problem solved

Functional benefit

Products and services

• Patent Prosecution Services Drafting and prosecuting U.S. and foreign patent applications for clients in the electrical, software, mechanical, and biomedical arts, with a stated focus on producing patents built from the ground up for litigation and licensing. Includes invention harvesting, continuation practice, and prosecution strategy supported by a two-tier internal review process. For enterprise clients (primarily Fortune 100/500 in-house IP departments).
• Patent Project Services (Pre-Litigation Consulting) Pre-litigation and litigation support services including unbiased assessment of strengths and weaknesses of patent issues (offensive and defensive), portfolio analysis (evaluating offers to license or purchase patent portfolios), product clearance / freedom-to-operate work, non-infringement and invalidity opinions, and trial testimony and opinion work. For corporate clients seeking independent prosecution-firm assessments outside their litigation counsel relationship.
• Trademark Services

Named customers14 records

Segments3 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability2 records

Feature5 records

Partnerships

Eight partnerships are on record, tiered minor, core and moderate.

• Chicago Hope AcademyminorOthersHFZ partners with Chicago Hope Academy, a Near West Side private Christian high school in Chicago. HFZ donated iPads and cases to support students and their families preparing for college. HFZ General Counsel Eileen Lysaught toured the campus with school administrators and student ambassadors.
• Intellectual Property Owners Association (IPO)coreGTM or Marketing PartnerHFZ is actively involved with IPO, a leading IP industry association. Chris George serves as Vice Chair of IPO's Software-Related Inventions Committee, leading sessions on US Patent Continuation Practice and AI/software IP. Chris also co-led a joint session of IPO's AI and Software-Related Inventions Committees at the 2025 IPO Annual Meeting in San Diego. Jim Flight spoke at the 2024 IPO Conference in Chicago.
• International Trademark Association (INTA)coreGTM or Marketing PartnerFounding members Jim Flight and Mark Zimmerman attend the INTA Annual Meeting (e.g., 2026 in London, May 2-6), which brings together more than 8,500 IP professionals worldwide. INTA provides educational programming on enforcement, valuation, transactions, and AI. HFZ provides trademark procurement services and manages clients' global portfolios.
• Association of Corporate Counsel (ACC) - Austin ChaptermoderateGTM or Marketing PartnerACC's Austin chapter sponsored a CLE presentation by HFZ Capital Members Marianne Buckley and Jim Flight titled 'Riding the AI Wave: How AI Tools and the USPTO's Newest AI Policies Can Lift Your Technology Portfolio,' delivered February 18, 2026 in Austin, Texas.
• Foreign patent counsel firms (international network)coreChannel Partner/ Reseller/ DistributorHFZ maintains relationships with patent law firms throughout the world to secure international and foreign patent protection for clients. HFZ drafts and prosecutes applications with advice from international attorneys abroad and provides advice to international attorneys assisting with preparation and prosecution of international patent applications. An International Filing Specialist on staff manages these relationships.
• Maiwald (German patent law firm)moderateStrategic or Co-development PartnerJames Flight spoke by invitation at the Maiwald Seminar: 'Protection and enforcement of software inventions in DE, KR and US' in Munich, Germany in June 2019. The Maiwald relationship reflects HFZ's international engagement with European patent prosecution partners.
• GE Aerospace ResearchcoreStrategic or Co-development PartnerHFZ Capital Member Chris George participated in the 2026 LEAD Symposium hosted by GE Aerospace Research in Niskayuna, New York, joining GE engineers, technical leaders, and external collaborators to discuss innovation in digital and electrical systems shaping the future of flight.
• American Conference Company (Women Leaders in IP Law Summit)moderateGTM or Marketing PartnerHFZ Capital Member Marianne Buckley attended the 6th Annual Women Leaders in IP Law Summit in Washington, D.C., hosted by American Conference Company. The summit brings together law firm practitioners, in-house counsel, government officials, and industry leaders to discuss emerging IP issues.

Scale indicators9 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• Banner Witcoff: Chicago-headquartered patent boutique with electrical, software, and mechanical prosecution focus. Comparable to HFZ in boutique size, technical depth, and prosecution-only business model, with overlap on marquee patent-owning clients.
• Oblon, McClelland, Maier & Neustadt: Virginia-based patent prosecution firm of similar size and philosophy, with strength in electrical, software, and mechanical prosecution. Closely comparable to HFZ on litigation-ready drafting and Fortune 500 client work.
• Leydig, Voit & Mayer: Chicago patent prosecution firm with similar size and a comparable electrical/software/mechanical/biomedical practice mix. Direct overlap with HFZ on patent quality rankings (IAM Patent 1000) and shared enterprise clients in the Midwest industrial base.
• Sterne, Kessler, Goldstein & Fox: Washington, D.C.-based dedicated patent prosecution and counseling firm of comparable size and philosophy. Closely comparable to HFZ on litigation-ready patent drafting, technical-attorney model, and Fortune 500 client roster.
• McDonnell Boehnen Hulbert & Berghoff (MBHB): Chicago-based intellectual property law firm with a comparable focus on patent prosecution and counseling. Overlaps with HFZ on technical depth, mid-sized practitioner bench, and Fortune 500 client base, making it the most direct geographic and practice-area peer.

Broad incumbents

• Fish & Richardson: Larger national IP-focused firm with significantly greater scale and a full-service IP litigation offering. Competes with HFZ for patent prosecution engagements at the same Fortune 500 clients but operates at materially greater scale and broader scope.
• Knobbe Martens: Large California-headquartered IP firm with prosecution and litigation across electrical, software, mechanical, and biomedical arts. Competes with HFZ for high-tech patent prosecution but with a much larger practitioner bench and West Coast orientation.
• Foley & Lardner: Large full-service law firm with a substantial IP practice including patent prosecution and litigation. Competes with HFZ on enterprise patent prosecution matters but offers a broader practice mix beyond IP.
• Finnegan, Henderson, Farabow, Garrett & Dunner: Large national IP firm with patent prosecution, litigation, and PTAB practices. Comparable to HFZ on enterprise prosecution quality (IAM Patent 1000 ranked) but with substantially broader geographic reach and litigation capability.

Emerging players

• Greer Burns & Crain: Chicago-based IP boutique with patent prosecution focus, smaller than HFZ but serving similar enterprise clients in the Midwest. Comparable niche positioning and overlap on Illinois-based IP counsel relationships.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/hanley-flight-&-zimmerman

Revenue estimate

Valuation estimate

Number of profiles

Profiles29 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Hanley Flight & Zimmerman