Gregory R. Hallmark is an experienced government contracts (GovCon) litigation attorney in Holland & Knight's Tysons office. He is well versed in prosecuting and defending bid protests before the U.S. Government Accountability Office (GAO), the U.S. Court of Federal Claims and at the agency level, having litigated more than 100 bid protests. He also assists clients with contract claims and litigates contract disputes before the Armed Services Board of Contract Appeals (ASBCA) and Civilian Board of Contract Appeals (CBCA).

In addition, Mr. Hallmark advises businesses on a range of issues, including compliance with the Federal Acquisition Regulation (FAR) and agency FAR supplements, compliance with federal grant regulations, False Claims Act (FCA) matters, subcontracts and teaming arrangements, requests for equitable adjustment (REAs), commercial item issues, cost and pricing matters, organizational conflicts of interest, terminations and small business regulations.

Representative Experience

  • Successfully challenged an agency's summary rejection of a client's proposal for alleged non-compliance with the solicitation's proposal instructions in a multiple-award competition worth up to $13 billion; as a result, the agency reinserted the client's proposal into the competition
  • Identified flaws in an agency's cost realism analysis of the awardee's and protester's proposals in a protest on behalf of an IT contractor, convincing the agency to terminate the award to client's competitor
  • Showed U.S. Government Accountability Office (GAO) that the awardee gained an unfair competitive advantage by failing to comply with solicitation's pricing requirements in a competition under General Services Administration (GSA) Schedule 70; GAO sustained the protest
  • Protested an agency's best value analysis on the basis that it did not reasonably consider the relative merits of proposals across all evaluation criteria, resulting in GAO predicting it would sustain the protest and the agency taking corrective action; the client ultimately received an award
  • Protested an agency's award to a competitor of a client, the long-term incumbent for the requirement, resulting in termination of the award and an award to the client


  • The University of Texas School of Law, J.D., with honors
  • University of Virginia, B.A., Government and Economics, with highest distinction
Bar Admissions/Licenses
  • District of Columbia
  • Virginia


Speaking Engagements