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Andrew J. Mahon
Associate
Back to All Professionals
Andrew J. Mahon
Associate
Contact
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York, PA

Lancaster, PA

Andy Mahon is an attorney in Barley Snyder’s Immigration and Employment practice groups with over a decade of experience. He concentrates his practice on immigration law, representing businesses and families seeking immigration benefits as well as defending individuals placed in removal proceedings. 

Andy manages a complex caseload of immigration matters for the firm. He  counsels a diverse range of businesses across industries including healthcare, dental, engineering, architecture, construction, manufacturing, technology, nonprofit, agriculture, and higher education. He works closely with his clients to address their full range of immigration needs. Andy guides clients through issues related to the Form I-9 process by assisting with the evaluation of employees’ authorization to work and the implementation of self-audits to ensure clients develop and maintain sound HR policies to promote consistency and compliance. He conducts comprehensive evaluations of foreign nationals’ eligibility for both temporary and permanent immigration statuses. He then develops tailored immigration strategies and oversees the exchange of information and progress among the legal team to ensure seamless execution of these plans. Additionally, Andy prepares and submits petitions and applications for a wide range of immigration statuses, including temporary statuses, such as E-2, H-1B, J, L-1, O-1, R-1, and TN, as well as permanent resident status through EB-1, EB-2, EB-3, and EB-4 classifications, navigating various paths such as Program Electronic Review Management (PERM) and National Interest Waivers (NIW). His business immigration practice also includes representing international medical graduates in applications for immigration status and securing 212(e) waivers through the Conrad 30 and HHS programs. 

Andy has represented hundreds of clients before various agencies that are responsible for administering U.S. immigration laws, including the U.S. Citizenship and Immigration Services, the U.S. Department of Justice and the U.S. Department of State. He also litigates immigration cases in federal court, filing petitions for review and submitting oral arguments before the U.S. Court of Appeals for the Third Circuit, and preparing mandamus and habeas petitions before the U.S. District Court for the Middle District of Pennsylvania. He routinely advises attorneys from other areas of practice on immigration matters affecting their clients, often working with criminal defense counsel to structure guilty pleas to avoid future immigration consequences. Additionally, Andy has presented on immigration topics at several training courses for lawyers, paralegals and community members.

Before joining Barley Snyder, Andy worked at a Lancaster law firm focused exclusively on the practice of immigration law, becoming a partner in 2019. Prior to that, he was a staff attorney for the Pennsylvania Immigration Resource Center where he defended individuals in removal proceedings who were most in need due to mental illness, poverty or persecution in their country of origin. He started his legal career as a law clerk for the Honorable Penny L. Blackwell in the York County Court of Common Pleas. 

Andy graduated from Fordham University with a bachelor’s degree in history and French. He then spent two years living in France and working as an English teacher. He earned his juris doctor from Widener University School of Law, graduating with honors. He was a member of the Moot Court Honor Society and Widener Law Journal.

MEMBERSHIPS
  • American Immigration Lawyers Association
AWARDS/RECOGNITION
  • Light of Liberty Award, Pro Bono Attorney of the Year (2014)
PUBLICATIONS/SPEAKING ENGAGEMENTS
  • “Preparing for an ICE Visit and Other Immigration Enforcement Actions,” Mid-Atlantic Fruit and Vegetable Convention (January 2026)
  • “Cultural Competence in Immigration Law,” The Knowledge Group On-Demand CLE Diversity Webinar (January 2026)
  • “Immigration Issues and How YCBA Can Help,” York Bar Association Bench Bar Conference (November 2025)
  • “I-9 Compliance in an Age of Increased Immigration Enforcement,” Northeast Manufacturer and Employer’s Association, 17th Annual Labor and Employment Law Summit (September 2025)
  • “Navigating Tariff & Immigration Compliance: Ethical Considerations for Financial Leaders,” Financial Executives International, Central Pennsylvania (September 2025)
  • “Understanding and Navigating the Immigration Process,” 2025 Pennsylvania Poultry Sales and Service Conference (September 2025)
  • “Immigration Law from Start to Finish,” National Business Institute Virtual Seminar (September 2025)
  • “Trump 2.0 – What HR Professionals Can Expect Under the Current Administration,” Lancaster SHRM (September 2025)
  • “Understanding the Rights of Immigrant Communities,” Pasa Sustainable Agriculture (August 2025)
  • “Immigration Rights and Representation,” Movement of Immigrant Leaders in Pennsylvania (June 2025)
  • “Virtual Lunch and Learn: Immigration Investigations Under the New Federal Administration,” Lancaster SHRM (May 2025)
  • “Community Workshop Series on Immigration,” Lebanon Valley Chamber of Commerce (May 2025)
  • “Form I-9 Compliance in the Trump Administration: Best Practices, Updates, and Work Authorization for Foreign Nationals,”  42nd Annual Barley Snyder Employment Law Seminar (May 2025)
  • “Immigration Enforcement Actions: Preparing and Planning, ” Lancaster Bar Association (April 2025)
  • “Immigration Law and Impact on Practice in Central PA,” Lippsitt’s-Cohen Inns of Court (March 2025)
  • “Intro to Immigration Law for Paralegals,” Institute for Paralegal Education Virtual Seminar (March 2025)
  • “H-1B Visas: The Feuds and the Fury Disentangled,” National Business Institute Virtual Webinar (February 2025)
  • Immigration Forum, Penn Stone (January 2025)
  • “Immigration Law Updates 2024-2025: What You CAN’T Miss,” National Business Institute Virtual Seminar (December 2024)
  • “H-1B Status Overview,” Widener University Commonwealth Law School (September 2024)
  • “Immigration HR 101,” LSHRM (July 2024)
  • “Form I-9: Best Practices, Updates, and Immigration Statuses,” 41st Annual Barley Snyder Employment Law Seminar (May 2024)
  • “Immigration Forum,” ABC Keystone Peer Group Presentation (April 2024)
  • “Immigration Forum,” ABC Keystone Peer Group Presentation (February 2024)
  • “Human Resource Hot Topics,” PennAg (October 2023)
  • “Intro to Business Immigration and I-9 Compliance,” Lancaster Area Paralegal Association 8th Annual Civil Conference (September 2023)
  • “Immigration Law Training,” Mennonite Central Committee, Presenter (2013-2017)
  • “Model Hearing Program:  Withholding-Only Proceedings,” PIRC and York Immigration Court, Presenter (May 2014)
  • “Immigration 101,” LAPA General Business Meeting (January 2013)
OTHER PROFESSIONAL EXPERIENCE
  • Former teaching assistant, Bordeaux, France
Andrew J. Mahon
Education
  • Widener University School of Law, J.D., cum laude
  • Fordham University, B.A.
Admissions
  • Pennsylvania
  • New Jersey
  • U.S. District Court for the Eastern District of Pennsylvania
  • U.S. District Court for the Middle District of Pennsylvania
  • U.S. Court of Appeals for the Third Circuit
Capabilities
Industries
Community Involvement
Lancaster Neighbor Fund

Board Member

Friends & Neighbors of Pennsylvania

Board Member

St. James Episcopal Church, Lancaster

Chancellor to the Vestry Board

Pennsylvania Immigration Resource Center

Volunteer lawyer and former board president

Volunteer Income Tax Assistance Program

Volunteer tax preparer

American Immigration Lawyers Association

2026 Annual Conference Planning Committee Member, volunteer lawyer and former liaison committee member

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