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Tammy Vonderhorst, CPA

Tax Manager

"Breaking down complex tax matters so clients understand what they must do to remain compliant is the key to minimizing their tax liabilities and securing their finances. "

Tammy Vonderhorst, CPA, knows each tax planning and compliance engagement poses unique challenges, opportunities and goals. That’s why she takes a genuine interest in creating a personal relationship with each client and working with them the way she’d work with her friends – including the occasional teasing and joking from time to time to remove any stress from the process.

It’s a philosophy that’s served her and her clients well for more than 25 years. Tammy, a tax manager with Councilor, Buchanan & Mitchell (CBM), helps individuals, trusts and estates, closely-held businesses and those with interests in the real estate industry go beyond planning for and preparing their income tax returns.

Tammy jumps right in to get the job done as efficiently as possible to eliminate confusion, minimize liabilities and remain compliant with the IRS. Her approach was front and center during the COVID-19 pandemic, which created constantly changing – and many unique – needs for clients. Tammy helped clients be compliant and avoid penalties on payroll tax matters related to government relief programs such as the Employee Retention Credit and qualified sick wages related to the Coronavirus Aid, Relief, and Economic Security (CARES) Act.

Professional Qualifications and Education

  • Certified Public Accountant (CPA), Maryland
  • B.S. Accounting, University of Delaware

Professional Associations and Activities


  • Elijah Watt Sells Certificate for outstanding achievement on the CPA exam