Dennis L. Duncan

Attorney Profile

Top Rated Lobbying Attorney in Sioux Falls, SD

Zimmer, Duncan & Cole
 | 5000 South Broadband Lane, Suite 119
Sioux Falls, SD 57108
Phone: 605-361-9840
Selected to Super Lawyers: 2011 - 2017
Licensed Since: 1973
Practice Areas:
  • Lobbying (40%),
  • Government Relations (30%),
  • Legislative & Governmental Affairs (30%)
Attorney Profile

Dennis Duncan is a partner with the South Dakota law firm Zimmer, Duncan and Cole. Mr. Duncan's practice focuses on government relations in industries such as health care, insurance, public power, oil pipelines and telecommunications. He has practiced before state and federal district courts in South Dakota, North Dakota, Minnesota and Nebraska. Mr. Duncan has also represented appeals cases before the Supreme Court of South Dakota and the United States Court of Appeals for the Eighth Circuit.

Mr. Duncan attended the University of South Dakota where he obtained his undergraduate degree and was accepted to the University of South Dakota School of Law. He received his law degree and was admitted to the South Dakota Bar in 1973.

A member of American League of Lobbyists and the National Health Lawyers Association, among others, Mr. Duncan has represented groups such as the Pharmaceutical Research and Manufacturers of America and the South Dakota Foundation for Medical Care. He has also been a lobbyist in the South Dakota Legislature since 1975.

Practice Areas
Lawyer Practice Area Pie Chart

Lobbying (40%)

Government Relations (30%)

Legislative & Governmental Affairs (30%)


Selected to Super Lawyers for 7 yearsbottom-image

Super Lawyers: 2011 - 2017

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About Dennis Duncan

Admitted: 1973, South Dakota

Professional Webpage:

Bar/Professional Activity:

  • U.S. District Court, 1974
  • South Dakota, 1973
  • Member, American Medical Association
  • Member, Doctors' Advisory Network
  • Member, Group Health Association of America
  • Member, Forum Committee on Health Law - American Bar Association
  • Member, National Health Lawyers Association
  • Member, Litigation Counsel of America
  • Member, Defense Research Institute, Inc.
  • Member, South Dakota Defense Lawyers Association
  • Member, American League of Lobbyists
  • Member, American Bar Association
  • Member, South Dakota State Bar Association

Pro bono/Community Service:

  • University of South Dakota School of Law, Dean Search Committee, 1993
  • Chairperson, Group Benefits Committee, University of South Dakota School of Law (2004-2009)
  • Chairperson, University of South Dakota School of Law, Law School Committee (1994-1998)
  • Director - University of South Dakota Law School Foundation
  • Continuing Legal Education Committee Committee

Representative Clients:

  • Heartland Consumers Power District (Electric Power Transmission and Generation)
  • South Dakota Library Association
  • University of South Dakota Alumni Association
  • Eli Lilly Pharmaceutical Company
  • Pharmaceutical Research and Manufacturers of America
  • South Dakota Health Care Association
  • South Dakota Collectors Association
  • South Dakota State Medical Association
  • TransCanada Corporation (Keystone and Keystone XL Products, a partnership between TransCanada and Conoco-Phillips)
  • Verizon Wireless
  • Allstate Insurance Company
  • South Dakota Insurance Alliance
  • South Dakota Association of Mutual Insurers

Educational Background:

  • University of South Dakota, B.A. in Government, Minors:  History and English, 1970

Industry Groups

  • Health Care
  • Insurance
  • Public Power And Oil Pipeline
  • Telecommunications
  • Find Me Online
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    Office Location for Dennis L. Duncan

    5000 South Broadband Lane
    Suite 119
    Sioux Falls, SD 57108

    Phone: 605-361-9840


    Dennis L. Duncan:

    Last Updated: 7/1/2016

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