Sean Keegan

Overview

Sean Keegan, a Principal in Ryan’s Real Property Tax practice, is based in the Firm’s Irvine office, where he advises clients on property tax consulting and assessment appeal strategies across California and select U.S. jurisdictions. He works closely with owners, investors, and operators of commercial real estate to resolve complex valuation issues and achieve defensible, market-aligned tax outcomes.

With more than three decades of experience in property tax representation, Sean brings deep expertise in assessment appeals involving newly constructed improvements, leasehold improvements and fixtures, ownership determinations, possessory interests, exemptions, and sales-related valuation issues. His background includes senior leadership roles with national and regional property tax firms whose practices were later acquired by Altus Group and subsequently by Ryan. Sean is widely recognized for his advocacy before county assessment appeals boards and for his practical approach to navigating accounting, appraisal, and property tax interpretations for complex assets, including multifamily, office, industrial, retail, hospitality, senior housing, life sciences, food processing, and data center properties.

Education & Qualifications

Juris Doctor, Pacific Coast University School of Law

(Ryan is not a law firm.)

Bachelor of Science, Business Administration – Finance, California State University, Long Beach

Experience & Achievements

Principal, Real Property Tax, Ryan, Irvine office

• Provides property tax consulting and assessment appeal representation across California

• Advises on valuation issues involving complex and special-purpose properties

Vice President, Property Tax, national property tax firm

• Managed Northern and Southern California real property assessment appeals

Executive Vice President and Principal, local property tax firm

• Led real and personal property tax consulting and representation across multiple states

Associate with predecessor firms acquired by Altus Group and Ryan

Former Chair of the Board, California Alliance of Taxpayer Advocates

Former Officer, California Alliance of Taxpayer Advocates

Member, Institute for Professionals in Taxation

Member, National Association of Real Estate Investment Trusts (NAREIT)