At Sisterson, we are proud of our history and excited about our future.

Sisterson's First 90 Years: Built on Decades of Trust

On July 1, D.G. forms D.G. Sisterson & Company along with J.R. Miller and Max Sieger. First clients are J.H. Hillman & Sons Company and the DuPuy family. Offices are
in the First National Bank Building, which is demolished in 1970 to make way for One PNC Plaza.


  • The stock market crashes and the great depression begins.

  • The American Institute of Accountants (AIA)  sets rules of professional conduct.

The Hillman Company buys the Grant Building out of bankruptcy and moves in – along with D.G. Sisterson & Co. – from the First National Bank Building.


  • The U.S. enters World War II.

  • The Taft-Hartley Labor Management Relations  Act passes and requires labor unions to prepare  financial statements.

  • The U.S. begins income tax withholding.


  • Max Sieger’s son, Ed, joins the Firm.

  • The American Institute of Accountants (AIA)  becomes the American Institute of Certified  Public Accountants (AICPA).


  • In 1964, D.G. retires and Max Sieger becomes Managing Partner of Sisterson.

  • In 1969, a scholarship is established at the University of Pittsburgh in D.G.’s name.

  • Congress passes a law allowing CPAs to represent  clients before the IRS.

  • The Tax Reform Act of 1969 enacts the Alternative Minimum Tax.


  • Ed Sieger named Managing Partner of  D.G. Sisterson & Company.

  • The University of Pittsburgh awards the first  Douglas G. Sisterson Fellowship.

  • The AICPA rescinds its ban on advertising  by public accounting firms.

  • The AICPA creates an SEC Practice Section and  a Private Companies Practice Section, both with peer  review and quality control requirements.


  • Firm grows significantly, roughly triples.

  • Audit practice grows substantially.

  • Bill Troup joins Firm in 1980; he and three others buy the Firm from Ed Sieger in 1984.

  • Dave Simpson named Managing Partner  in 1988.


  • Firm becomes Sisterson & Co. LLP.

  • Bill Troup named Managing Partner in 1997.

  • New evaluations and rewards program created.

  • Expansion of consulting practice.

  • Firm admits first female to partnership.

  • Strategic marketing focus.

2000 - 2010

  • Alternate work arrangements introduced.

  • Sisterson joins AGN International.

  • Firm accolades – one of the 50 Best Places to Work  in Western PA and one of the Best Accounting Firms  to Work for in the nation.

  • Dress code moves from ‘business’ to ‘business casual’.

  • The Sarbanes-Oxley Act is passed, creating the Public  Company Accounting Oversight Board (PCAOB) to set  public company auditing standards.

2010 - present

  • Brad Lusk named Managing Partner in 2013.

  • Succession planning focus/orderly retirement  of partners.

  • Formalization and growth of niche teams.

  • Leadership Sisterson introduced, along with Women’s Initiative and Young Professional Group.

  • Sisterson recognized as one of the largest, independently owned accounting firms in the Pittsburgh region.