Office Location
San Diego, CA

Sam Mascareno

West Market Leader, Partner

About Sam

Sam Mascareno is tax partner and leader of the West market region for RSM US LLP. He is responsible for the strategy, growth and results for 11 western states. He is the executive sponsor for key firm-wide initiatives involving RSM’s client and talent experience, and he is part of the tax leadership team.


Based in RSM’s San Diego office, Sam oversees operations for high-performing teams in the West market that are focused on being first-choice advisors to middle market companies. He joined RSM in 2001 and has extensive experience providing tax services, including tax compliance, consulting and structuring. He serves as executive sponsor of RSM’s client experience, where he develops strategies on how to best align teams to provide the highest level of client service. He is also responsible for the design and oversight of RSM’s new partner experience. 

Born and raised in Mexico, Sam came to the United States at the age of 16. Prior to RSM, Sam specialized in tax at a Big Four firm in California and spent one year in Mexico learning the complexities of Mexican tax law. He gained experience in cross-border tax planning and international tax law during that time. He has extensive experience with large-scale projects and tax consulting for international clients with foreign ownership and or operations. He was previously part of RSM’s federal credits and incentives group, and he is extremely knowledgeable about research and development credits and incentives, domestic manufacturing deduction, and cost segregation studies within a variety of industries, including life sciences, technology and manufacturing. 

Sam is invested in the talent experience at RSM and serves as a guide and mentor for younger professionals in the firm. He is passionate about the experiences that RSM creates for its people and clients, as well as the firm’s strategic focus on the middle market. He appreciates being part of a firm that provides every employee the opportunity to maximize his or her potential. He believes that RSM’s investment in culture and a values-based workplace are the “secret sauce” that makes the firm successful and a great place to work.  

Sam is also passionate about providing access to educational opportunities for others. He has worked with the RSM Foundation to sponsor a junior college sponsorship for ethnic minorities to pursue a four-year degree and a career in public accounting based on the need for first-generation college students and business professionals to have a framework for success. 

Sam is also the co-founder of ¡Hola!, the firm’s employee network group (ENG) for Hispanic and Latino professionals and part of the firm’s Inclusion Council overseeing all of RSM’s ENGs.

Professional affiliations and designations

  • Certified professional accountant 

  • American Institute of Certified Public Accountants 

  • San Diego State University School of Accountancy, board member

  • Lighthouse Church, ordained pastor and co-founder 


  • Bachelor of Science, accounting (honors), San Diego State University – California State University 
  • Master of Science, tax (honors), San Diego State University – California State University