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

08.11.25

ORBA Ranked as a 2025 Top 200 Firm by INSIDE Public Accounting
CHICAGO — ORBA, one of Chicago’s largest public accounting firms, has once again been recognized as a 2025 IPA Top 200 Firm by INSIDE Public Accounting (IPA). This marks the eleventh time since 2013 that ORBA has made the list of the country’s top firms. In the IPA’s annual report, ORBA is ranked #113, climbing five spots higher than last year, and is the highest ranked of the six Illinois firms on the Top 200 list.

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Guides

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

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