Executive Team

The Executive Team is made up of Department leaders who are in charge of carrying out our mission and vision.


Kim Bimestefer
Executive Director

Kim Bimestefer was appointed by Governor John Hickenlooper to serve as Executive Director in January 2018.  As Executive Director, Bimestefer oversees the operations and strategic direction of the Department of Health Care Policy and Financing. The Department’s budget is more than $10 billion and is the single state agency administering Colorado Medicaid (Health First Colorado) and the Child Health Plan Plus (CHP+) program. Bimestefer directs the Department’s efforts to improve the health of 1.3 million Medicaid and CHP+ members and increase access to care across the state while containing costs.

Bimestefer was president and general manager of Cigna Mountain States and chair of Cigna Healthcare of Colorado before starting her own health care management consultancy. Bimestefer also founded and spent ten years as president and general manager for Cigna’s Taft-Hartley & Federal Business Segment. She began her health care career at a nonprofit insurance company, rising to a board-appointed officer overseeing about half the company’s membership and revenue.

Bimestefer has been active in the Colorado Forum, Colorado Concern, and the Colorado Women’s Chamber. She has served on many boards including the Colorado Association of Health Plans, the Metro Denver Economic Development Corporation, the American Heart Association, and the Precious Child Advisory Board. She also has chaired several community events, such as the American Cancer Society’s CEOs against Cancer.

She earned her bachelor’s degree from Towson State University and her MBA from Loyola College of Maryland. She is also a graduate of the Wright Management Group and Darden School of Business, Executive Leadership Programs.


Tom Massey
Deputy Executive Director and Chief Operations Officer

Tom Massey is the Deputy Executive Director and Chief Operations Officer at the Department of Health Care Policy and Financing. He is responsible for the management of government relations, internal and external communications, human resources, workforce development and facility operations.

Prior to coming to the Department, Massey served as a state legislator representing Colorado House District 60 (Poncha Springs, Salida) for eight years. He was a member of the Health and Environment Committee and chaired the House Education Committee. He sponsored several pieces of health care legislation, some of which included prescription drug monitoring, home health care, health information technology and electronic prescriptions in Health First Colorado (Colorado's Medicaid Program). He also received numerous legislative honors, including awards from the Colorado Chapter of the American Academy of Pediatrics, Leadership for Healthy Communities, Colorado Substance Abuse Peer Services, and the Colorado Home Health Care Network.

Massey has been a member of the Colorado Child Welfare Commission, served on the Health Information Exchange Board, the Health Information Technology Advisory Board and has been a Colorado Health Foundation Fellow. He served on the Board of Directors for the Children’s Health Foundation. He also owned and operated four Coldwell Banker franchises in central and southern Colorado.

Massey received his Bachelor of Arts Degree from the University of North Texas.


John Bartholomew
Finance Office Director

John Bartholomew is the Finance Office Director of the Department of Health Care Policy and Financing. Bartholomew has been a member of the HCPF team for over 16 years. Prior to taking on his role as the Chief Financial Officer, John served as an economist, a statistical analyst, the director of the Rates and Analysis Division, and the Budget Director for the Department. In the past few years, he has played an instrumental role in finding departmental budget savings and assisting the Governor’s budget office in submitting balanced budgets.

Prior to joining the Department, Bartholomew was the lead economist at the Business Research Division at the University of Colorado, Boulder. He has served on the board of the Denver Association of Business Economists from 2000 to 2009 and completed a fellowship at the Colorado Health Foundation.

John has a Master’s degree in Economics from the University of Colorado, Boulder and received his bachelor’s degree from the University of California, Santa Barbara.


Carrie Cortiglio
Policy, Communications, and Administration Deputy Director

Carrie Cortiglio is the Deputy Director of the Policy, Communications and Administration Office at the Department of Health Care Policy and Financing.

Prior to her current role, she was the Department’s legislative liaison. Before joining the Department, Cortiglio worked as a policy analyst for the Health District of Northern Larimer County. Her work there focused on all aspects of health care policy, including health care reform, and she led the Health District’s efforts to create a community-wide strategy to reduce consumption of sugar-sweetened beverages. Prior to relocating to Colorado, Cortiglio worked for the Massachusetts legislature and for Congresswoman Rosa DeLauro.

Cortiglio holds a Master's of Science from the Harvard School of Public Health and a bachelor’s degree from Dickinson College. She is a graduate of the 2010 Advanced Leadership Training Program Regional Institute of Health and Environmental Leadership (RIHEL).


Gretchen Hammer
Medicaid Director

Photo of Medicaid Director Gretchen Hammer

Gretchen Hammer is the Department’s Medicaid Director and oversees the Health Programs Office which administers Health First Colorado (Colorado's Medicaid Program) and Child Health Plan Plus (CHP+) health program benefits, delivery systems and provider relations.

Before joining the Department, Hammer was Executive Director of the Colorado Coalition for the Medically Underserved (CCMU). She served as past Chair and Member of the Connect for Health Colorado Board of Directors, served on the Colorado Children’s Healthcare Access Program (CCHAP) Board and HealthONE Board of Trustees. Prior to her work at CCMU Ms. Hammer was a private consultant focused on leadership development, complex systems change initiatives, strategic planning, program management and constituent engagement for numerous public serving organizations.

Hammer received a B.A. from Colorado College and a holds a Master's of Public Health from the University of Washington School of Public Health and Community Medicine.


Laurel Karabatsos
Delivery System and Payment Innovation Division Director and Deputy Medicaid Director

Laurel Karabatsos is the Director of the Delivery System and Payment Innovation Division at the Colorado Department of Health Care Policy and Financing. Karabatsos leads the Department’s work innovating, testing and refining new ways to deliver and pay for health services. She is committed to finding ways to make health care work better for Health First Colorado (Colorado's Medicaid Program) members while controlling costs for the state, to ensure the long-term viability of Health First Colorado for Coloradans who need it.

Most recently, Karabatsos has been leading reform through the Accountable Care Collaborative, a program that gives Health First Colorado members their full benefits while emphasizing coordinated care and good health outcomes. She laid the foundation for a thoughtful, step-wise approach to reform that makes the most of Colorado’s strengths while moving the state toward greater accountability for health care spending. Laurel and her team continue to build on this work by testing payment and delivery reform innovations within the Accountable Care Collaborative model.

Karabatsos' work with Health First Colorado began in 2001 when she managed the Quality Improvement section of the Department. As the leader of Health First Colorado’s program integrity and quality functions, Laurel measured health outcomes and client satisfaction across managed care and fee-for-service programs. She evaluated managed care health plan performance and set policies for utilization management.

Karabatsos holds a Master of Organizational Management degree from the University of Phoenix and a Bachelor’s Degree in Sociology and Women’s Studies from the University of Colorado.


Antoinette Taranto
Chief Client Officer

Antoinette Taranto is the Department’s Chief Client Officer. Taranto has more than 19 years of experience in health policy and administration, 16 of which are at the Department. She leads the customer experience and engagement strategy, creating greater customer value through customer centric culture.

Since joining the Department, Taranto has focused on improving services to both providers and clients by streamlining business and systems operations, customer service, and expanding enrollment and outreach. Through Taranto’s leadership, Coloradans can apply for benefits online and receive instant decisions, and county workers have improved systems and processes to assist customers. Taranto has been honored as a manager of the year and selected to speak at many local and national events.

Prior to her career with the Department, Taranto obtained private health insurance, hospital and clinic administration experience.

Taranto is a member of the Institute of Industrial Engineers and the Project Management Institute Mile Hi Chapter. She serves on the Board of Directors for the Rocky Mountain JDRF and holds the position of Outreach Chair. She has a Bachelor of Science in Health Policy and Administration from Pennsylvania State University, a Certificate of Graduate Studies for Database Administration from University of Denver, and Lean Six Sigma Green Belt and Project Management Professional Certifications.


Chris Underwood
Health Information Office Director

Chris Underwood serves as the Office Director of the Health Information Office for the Department of Health Care Policy and Financing.

Underwood joined the Department in 2000 as a statistical analyst. During his time with the Department, he has held the position of manager and division director over various areas. At present, he is responsible for developing strategies for systems development and operations for client and provider eligibility, health care claims processing, and health information technology on behalf of the Department. In addition, he has oversight of the Department’s purchasing and contracting services. Previously he had oversight of the Safety Net Programs Section, which included administering the Colorado Indigent Care Program, Old Age Pension Health and Medical Care Program, School Health Services Program, and numerous projects to maximize federal Health First Colorado (Colorado's Medicaid Program) revenue. Other supervisory roles included oversight of Health First Colorado eligibility policy and operations, the calculation of managed care and hospital rates, external and internal audits to investigate waste and abuse in the Health First Colorado program, and analytical analysis and statistical reporting for the Department. He represents the Department on the Hospital Provider Fee Oversight and Advisory Board and several task forces and boards related to ending homelessness and individuals involved in the criminal justice system.

Underwood holds a Master’s Degree in Economics from the University of Colorado, where he also received his undergraduate degree in Economics. Still maintaining his interest in economics, he served on the board of the Denver Association of Business Economics and served as president of the board from 2001-2004.


Judy Zerzan, MD, MPH
Chief Medical Officer and Client and Clinical Care Office Director

As Chief Medical Officer, Dr. Zerzan provides clinical guidance for medical and pharmacy benefits and directly oversees the Pharmacy and Quality & Health Improvement units. Dr. Zerzan has a role in the design and implementation of benefits design, Colorado’s Accountable Care Collaborative, quality and health outcome improvement, and cost-containment efforts. She is also a Clinical Assistant Professor in the Division of General Internal Medicine at the University of Colorado Denver.

Zerzan received her MD degree from Oregon Health and Science University in 1998 and her MPH in Health Policy and Administration from the University of North Carolina in 1999. She completed the Robert Wood Johnson Clinical Scholars Program at the University of Washington/Seattle VA in 2007. Dr. Zerzan was a 2008-2010 nonresidential Health and Aging Policy Fellow in the office of Senator John D. Rockefeller IV of West Virginia. During her fellowship, she worked on Medicaid, benefits for those dually-eligible for Medicare and Medicaid, and prescription drug policies. Dr. Zerzan currently serves as past-chair of the AHRQ sponsored Medicaid Medical Director’s Learning Network.