McMahon & Tivnan, PC Employee Directory

Law PracticeMassachusetts, United States2-10 Employees

McMahon & Tivnan, PC is a Boston, Massachusetts-based law practice focused on federal and state tax matters. The firm represents individuals, estates, and businesses through audits, liability disputes, and collection efforts, defending IRS and state tax issues and, when necessary, pursuing disputes in court. Led by D. Sean McMahon and Ryan Tivnan, the team combines more than a century of collective experience in investigating and defending tax issues.

They provide insights into the real risks presented by tax disputes and planning for complex transactions across corporate, real estate, partnership, securities, and options contexts. They advise clients on the tax considerations of these arrangements and have extensive experience assisting individuals with foreign transaction reporting and penalty disputes, including FBAR requirements and cryptocurrency transactions.

Find McMahon & Tivnan, PC employees' phone numbers or email addresses

McMahon & Tivnan, PC Global Highlights

Location
Employees

North America
10

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  • United States Of America
    10

McMahon & Tivnan, PC's Leadership

  • Stylized image of a person
    S. M.
    Partner
    Phone icon
  • Stylized image of a person
    R. T.
    Partner
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  • Stylized image of a person
    A. M.
    Tax Attorney
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  • Stylized image of a person
    G. O.
    Cpa, Mst
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  • Stylized image of a person
    J. C.
    Business Administrator
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  • Stylized image of a person
    K. W.
    Associate Attorney
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  • Stylized image of a person
    K. W.
    Associate Attorney
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  • Stylized image of a person
    W. W.
    Irs Tax Attorney
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McMahon & Tivnan, PC Employee Metrics

100%
50%
0%
2026
2025
  • Legal
  • Accounting
  • Administrative
  • Analytics
  • Arts & Design
  • Other

Contact profiles from McMahon & Tivnan, PC

Name
Title
Contact Info
Location
Last Update
  • Stylized image of a person
    S. M.
    Partner
    Phone icon
    United StatesMassachusetts
    Apr 16, 2026
  • Stylized image of a person
    R. T.
    Partner
    Phone icon
    United StatesMassachusetts
    Apr 17, 2026
  • Stylized image of a person
    A. M.
    Tax Attorney
    Phone icon
    United StatesMassachusetts
    Apr 16, 2026
  • Stylized image of a person
    G. O.
    Cpa, Mst
    Phone icon
    United StatesMassachusetts
    Oct 23, 2025
  • Stylized image of a person
    J. C.
    Business Administrator
    Phone icon
    United StatesMassachusetts
    Oct 19, 2025
  • Stylized image of a person
    K. W.
    Associate Attorney
    Phone icon
    Oct 22, 2024
  • Stylized image of a person
    K. W.
    Associate Attorney
    Phone icon
    United StatesMassachusetts
    Apr 18, 2025
  • Stylized image of a person
    W. W.
    Irs Tax Attorney
    Phone icon
    Oct 21, 2024

Frequently Asked Questions

What is McMahon & Tivnan, PC known for?

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McMahon & Tivnan, PC operates in the Law Practice industry. The company's main headquarters is located in 100 High Street Suite 2601 Boston, Massachusetts United States; you can contact the main corporate office by phone at . Explore McMahon & Tivnan, PC's company overview page for more information.

What is McMahon & Tivnan, PC's most common email format?

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McMahon & Tivnan, PC employees' email format typically follows the pattern of . Trying to find reliable and up-to-date employee contact data? Find more McMahon & Tivnan, PC email formats with LeadIQ.

How many employees does McMahon & Tivnan, PC have currently?

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McMahon & Tivnan, PC has approximately 9 employees as of May 2026. These team members are located across 1 continents, including North America.

Who are McMahon & Tivnan, PC's key employees and leadership?

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As of May 2026, McMahon & Tivnan, PC's key employees include:

  • Partner: S. M.
  • Partner: R. T.
  • Tax Attorney: A. M.
  • Cpa, Mst: G. O.
  • Business Administrator: J. C.

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