Derek Hammen, <span class="title">CPA, CFE</span>

Derek Hammen, CPA, CFEAudit Manager

P 312.670.7444 | F 312.670.8301

Derek Hammen is an Audit Manager and member of the firm’s Audit Group. His accounting and audit experience is extensive, having served in previous roles as a consultant, controller and manager on audit engagements of middle market companies primarily in the manufacturing distribution and technology industries.  He is adept at researching and understanding technical accounting matters to create accounting policies and memorandums for accounting treatment. 

Derek also assists in the firm’s Audit & Assurance Quality Control by performing internal inspections, providing technical consultations, and conducting trainings for the firm’s Audit Group.

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Firm News


ORBA’s Stephanie Zaleski-Braatz Appointed to Illinois CPA Society’s Board of Directors
CHICAGO — ORBA, one of Chicago ’s largest independent accounting, tax and consulting firms, is pleased to announce that Stephanie Zaleski-Braatz, CPA has been named to the Illinois CPA Society's (ICPAS) Board of Directors. She will serve in this role for a three-year term through March 2027.

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seminars & events


ORBA will gladly provide you with hard copies of the useful guides listed below. Select which guides you would like to receive and submit the form below.

  • Tax Pocket Guide
  • Tax Planning Guide
  • Records Retention Schedule
  • Auto, Travel & Business Log

request guide

Forward Thinking
Forward Thinking