Daniel K. Mannion



Daniel K. Mannion focuses his practice in the areas of health law, medical malpractice defense, commercial litigation and transportation law. He has extensive experience representing clients in all phases of litigation in both state and federal courts, from the filing of a claim or lawsuit through trial and appeal.

Dan routinely represents health care providers in medical negligence and wrongful death cases, as well as proceedings before administrative agencies and licensing boards. He also has significant experience in the area of corporate health care law, with an emphasis on corporate transactions, fraud and abuse, compliance and the negotiation and drafting of various vendor, employment and professional services agreements. He has spent a large part of his career working with health care clients to develop actionable strategies to mitigate risk and improve the quality of care.

Dan also regularly represents clients in commercial litigation, premises liability and transportation related matters, including serious vehicular and trucking accidents, and catastrophic casualty claims.

Professional Associations

  • Missouri Organization of Defense Lawyers
  • Defense Research Institute, Inc.
  • Transportation Lawyers Association
  • USLAW Network, Inc.
  • American Bar Association
  • Bar Association of Metropolitan St. Louis
  • The Missouri Bar

My Team

Administrative Assistant:
Lisa Corley

Bridget O. Briggs

Practice Areas

  • Transportation
  • Insurance Defense
  • Medical Malpractice
  • Health Care
  • Premises Liability
  • Commercial Litigation
  • Personal Injury Defense

Bar Admissions

  • Supreme Court of Missouri
  • U.S. District Court Eastern District of Missouri
  • U.S. District Court, Central District of Illinois
  • U.S. Court of Appeals 8th Circuit


  • University of Missouri-Columbia School of Law, Columbia, Missouri
    • J.D., 2000
  • Indiana University
    • B.A., 1995

Employment History

  • Lashly & Baer, P.C.
    Member, 2021 – Present
    Attorney, 2017 – 2020
  • Bauman Law Firm, P.C.
    Attorney, 2007 – 2017
  • Carmody MacDonald, P.C.
    Attorney, 2004 – 2017
  • McCarthy, Leonard & Kaemmerer, L.C.
    Attorney, 2001 – 2004
  • Missouri Court of Appeals, Eastern District
    Attorney/Law Clerk, 2000 – 2001
    Intern, 1997 – 1999

Contact Our Attorneys Today

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Plan Your Visit

Lashly & Baer, P.C.


714 Locust Street

St. Louis, MO 63101

Map & Directions

Call: 314-621-2939

Fax: 314-621-6844


20 East Main Street
Belleville, IL 62220

Map & Directions

By Appointment Only
Call: 618-233-5587
Fax: 314-621-6844