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Management Team

Leigh Hutchins, MBA, CEO of NAMM California and COO of OptumCare Southern California
Leigh Hutchins is the CEO of NAMM California and PrimeCare Medical Network, Inc. (PMNI), affiliate organizations partnering with physicians to provide better quality and more affordable care to the residents they serve in Southern California. NAMM and PMNI serve over 230,000 members in Riverside, San Bernardino, and San Diego counties through 16 Independent Practice Associations (IPAs) comprised of over 600 contracted Primary Care Physicians. NAMM and PMNI partner with all of the major HMO carriers in Southern California for both commercial and Medicare lines of business. PMNI and NAMM have been recognized as Best Medical Group and Top Workplace in the region. Ms. Hutchins has over 25 years of progressively responsible health care management experience. She joined NAMM in 1993 and has held various positions with NAMM/PMNI in the areas of payor and provider contracting, network development, transactional services and IPA operations. Prior to joining NAMM, Ms. Hutchins worked for FHP HealthCare in both staff model and IPA operations. Her commitment to promoting the wellbeing of her communities has led to her active participation in charitable organizations such as the American Heart Association, the Juvenile Diabetes Research Foundation and the American Cancer Society. Ms. Hutchins is a Board Director for CAPG, a trade association for Accountable Physician Groups. She sits on the Integrated Healthcare Association’s Technical Payment Committee in support of the Pay for Performance Program. Ms. Hutchins received her B.A. degree with honors in Pharmacology from the University of California, Santa Barbara and her M.B.A. from the Anderson Graduate School of Management at the University of California, Los Angeles.

Jamie Phillips, President
Jamie Phillips is the President of NAMM California and PrimeCare Medical Network, Inc. (PMNI) affiliate organizations and joined NAMM in October 2016. Ms. Phillips has over 30 years’ experience in healthcare and Medical Practice Management. Prior to joining NAMM she worked at DaVita HealthCare Partners (HCP) since 2004 and held several high level positions including Senior Vice President of Operations and most recently, Senior Vice President of the New Market Integration team. Ms. Phillips also worked for CareMore Medical Management Company and for Galaxy Healthcare South Africa. She has an extensive background that encompasses all areas of managed care including both IPA and Medical group operations, network development and population management. Ms. Phillips previously served as the Chairman of the Long Beach Network for Health, a community HIE initiative. She is an Alumni of and advisor to the California Healthcare Foundation, Leadership Fellowship. She earned her BS in Nursing from Creighton University and her Masters in Health Administration from the University of LaVerne. Her clinical background coupled with her business education and experience position her well to help NAMM navigate the ever changing healthcare landscape.

Verni Jogaratnam, MD, Sr Vice President, CMO
Dr. Jogaratnam assumed the role of Sr Vice President and Chief Medical Officer in January 2016. His career spans over 26 years as both a practicing physician and health plan executive in corporate and clinical settings. He has a proven track record in managed care and implementing quality driven innovations to ensure outcome excellence and appropriate utilization. Dr. Jogaratnam has experience in Medicaid, Medicare, and commercial lines of business and his previous responsibilities included cost containment, Stars, HEDIS, and RAF performance. Most recently, Dr. Jogaratnam served as the CMO for the UHC Community Plan in Seattle, WA. He is trained in both pediatrics and internal medicine at the Yale University Program at Bridgeport Hospital and received his MMM in Medical Management from the University of Southern California.

Marshall Veerkamp, Sr Vice President, CAO
Mr. Veerkamp has over 15 years’ experience in healthcare management. In this role, he oversees the PrimeCare Independent Practice Associations (IPAs) as well as the Risk Adjustment. Mr. Veerkamp has worked as a consultant for multiple healthcare delivery systems, provided executive leadership for large organizational-wide change initiatives, and developed and managed service offerings for external clients. He holds a M.B.A. from the University of Michigan – Ross School of Business, a B.S. in Management Information Systems from California State University at Chico, and he possesses numerous industry certifications and affiliations.

Jennifer Rapp, Sr Vice President, COO
Ms. Rapp joined NAMM California in October 2017. In this role, she is responsible for defining and executing the strategy for NAMM's provider-centric operations inclusive of Network Operations, Customer Service and Provider Contracting. Additionally, she is responsible for developing, implementing and overseeing the strategic relationships with NAMM’s provider and hospital partners. Most recently, Jennifer was responsible for Provider Experience and Operations for UnitedHealthcare's Community and State Division (Medicaid) where she led a national team focused on improving the way we support and engage with our providers to not only drive an improved provider experience, but also impact the member experience as well. Prior to that role, Ms. Rapp spent nearly 13 years at Cigna and has over 20 years of experience in the healthcare industry. She has extensive experience in managing large scale Operations (Claims, Call, UM, Data Integrity), Network Development and Provider Relations, Portfolio Delivery and Execution, as well as Member/Consumer Engagement solutions.

Greg Prieto, CIO
Mr. Prieto joined NAMM California in May 2018. Mr. Prieto has over 16 years of IT Leadership experience with 13 of those years in HealthCare IT. Prior to joining NAMM, Mr. Prieto was the Director of Information Technology Services for Monarch HealthCare and OptumCare Medical Group where he led Infrastructure and Operations Teams. In addition to experience in IPA and Clinical IT management, Mr. Prieto has experience leading IT services in a hospital setting while assigned as the IT Director for Riverside Community Hospital. Mr. Prieto has extensive experience in leading initiatives ranging from acquisition integrations, process improvements, data center management, and security compliance. In addition to an MBA, Mr. Prieto holds numerous industry certifications and recently completed an Executive Leadership and Management Certification Program from the University of Notre Dame, Mendoza College of Business.

Howard Siegel, MD, Sr Regional Medical Director
Dr. Siegel is the Senior Regional Medical Director and joined NAMM California in May 2013. Born and raised in New York, Dr. Siegel attended Universidad Del Noreste, School of Medicine in Mexico and did a Fifth Pathway thru New York Medical College. He is a Board Certified Pediatrician, originally from Maimonides Medical Center/Coney Island Hospital in New York. Dr. Siegel relocated to Southern California in 1992 and comes to us from Regal Medical Group where he held the position of Regional Medical Director with primary responsibility over Utilization, Quality, Contracting and Hospital Relations for their South Region for 8 years. Prior to that, he worked with Gateway Medical Group overseeing Pediatric and Adult Utilization Review and Staff Pediatrician. Dr. Siegel’s current responsibilities with NAMM include direct oversight for several aspects of outpatient utilization management and care coordination services. He (and a colleague) recently participated and won the OptumCare Clinical Transformation Challenge.

Nick Marciano, MD, Sr Regional Medical Director
Dr. Marciano has been with NAMM California since April of 2008. While with the company, he has been involved in all aspects of Medical Management including Utilization Management, In-Patient Management, Ambulatory Care Management, Quality Management, and Peer Review, both at the corporate level as well as the local IPA level. Prior to his NAMM position, he worked at Primary Provider Management Company (Medi-Cal line of business), Northridge Medical Group, and Riverside Physicians Network, all as full-time medical director. Prior to his administrative work, he was a practicing general surgeon at the Riverside Medical Clinic and subsequently as an independent practitioner in Riverside. He is presently in a part-time role, focusing on development of an advanced care panel of specialty providers capable of performing advanced procedures in the local community hospital setting. In addition, he is helping to develop an education series for internal staff on the various aspects of medical management roles and functions.

Eric Gureghian, MD, Sr Regional Medical Director
Dr. Eric Gureghian assumed the role of Regional Medical Director in 2016, focused on inpatient care and transitions, and is now one of the Sr Regional Medical Directors. He possesses extensive experience in Patient Care and Managed Care Medical Management, to include high risk Case Management, Utilization Management, Physician Education and Provider Relations. Dr. Gureghian is passionate about providing high quality, cost effective healthcare and leading other healthcare professionals in achieving the same goals. His previous role was serving in a lead physician capacity for Regal Medical Group in Southern California. Dr. Gureghian is Board Certified in Internal Medicine. He works closely with Dr. Marciano overseeing NAMM's In-Patient Management program.

Jason Chung, MD, Regional Medical Director
Dr. Chung joined NAMM California in April 2017. In this role, he will fully support Quality, Care Planning efforts across NAMM, work closely with our Senior Regional Medical Director in the outpatient utilization management space, and oversee several IPAs within our region. Dr. Chung join us from WellStar Health System in Georgia, a 11-hospital provider network, where he served as AVP Physician Advisor with responsibilities involving utilization management, quality improvement and care coordination. Prior to WellSar, he was in clinical practice at Kaiser Permanente in Oakland, where he specialized in medical imaging and nuclear medicine. Dr. Chung attended Tufts University in Boston, where he obtained his MD and MBA degrees. His other interests include conflict resolution, predictive analysis and discovering new restaurants.

Trisha L. Daniels, Vice President, Contracting, Claims and Configuration
Ms. Daniels has over 20 years of managed care experience in the areas of payer and provider contracting, claims, and managed care operations. She has worked for MSO entities and has managed physician practices. Ms. Daniels joined NAMM in March of 2003. Prior to assuming contracting responsibilities in 2006, Ms. Daniels was the Director of Transactions. Her current areas of responsibility include health plan negotiations, hospital and network contracting operations, claims and EDI transactions; including provider and benefit configuration, eligibility and capitation expense processing in the company's managed care system.

Don Thompson, Vice President, Finance
Mr. Thompson has more than 20 years of experience in the accounting and auditing fields. He began his career with an international public accounting firm and has worked in the health care industry since 1991, in both hospital and managed care settings. Mr. Thompson joined PrimeCare in 1997. He is currently responsible for oversight of the Accounting, Eligibility and Capitation departments, including financial and health plan reporting, investment and treasury management, financial and regulatory audits, California Department of Managed Health Care reporting, member eligibility maintenance and provider capitation payments.

Patricia Gutierrez, Vice President, Human Capital
Ms. Gutierrez has more than 20 years’ experience in Human Resources in the areas of health care and management. She joined NAMM in March 1997 following a career in the manufacturing industry. Since that time, the Human Resources Department has been a critical component in complying with all labor laws and has kept the company from discrimination/harassment lawsuits. Her current responsibilities include oversight of all HR functions, including recruitment and retention programs, management training and company-wide customer service educational programs. Ms. Gutierrez is an active participant in the Employer's Group (Human Resources Organization) and Society of Human Resources Management.

Demara Nuzum, RN, BSN, Vice President, Medical Management
Ms. Nuzum has more than 20 years of managed care experience in the area of medical management, which has included UM, QI, credentialing, risk management and case management. She also has worked as a private consultant for health plans and with IPA/MSO entities in the area of medical management, as well as assisting in preparation with regulatory audits and DHMC license filings. Ms. Nuzum joined NAMM in June of 2002 as Director of Corporate Compliance. In May of 2004, Ms. Nuzum assumed responsibility for Medical Management. She has always maintained an active role in ICE, serving on numerous workgroups focused on standardization of medical management processes.

Amber Romero, Vice President, Legal Affairs
Ms. Romero joined NAMM in April 2016. She has over ten years of experience in the health care sector and has been a practicing attorney for seven years. She received her JD degree from Western State University College of Law and holds a B.A. in Finance from the University of Wisconsin-Milwaukee. Prior to NAMM, Ms. Romero worked at Apria HealthCare and prior to that, held positions at Assurant Health, Quest Diagnostics, and Johnson & Johnson. She has deep experience with provider and payor contracting and enjoys supporting the business by providing legal advice on laws and regulations, risk mitigation, and dispute resolution.

Vicki Medlen, LVN, Associate Vice President, Quality Improvement
Ms. Medlen has more than 20 years of managed care experience in the area of medical management, which has included QI, credentialing, and UM. Ms. Medlen joined NAMM in September of 2002 as a UM Supervisor and moved to Quality in 2003. She is active on ICE teams, and has lead the organization in various quality collaboratives to improve the health of our members.

Shawna Kamper, M.S.H.S.A, Associate Vice President, Transactional Services
Ms. Kamper has over 16 years of managed care experience in the areas of network operations, health plan contracting, and claims operations along with managed care operations. Ms. Kamper joined NAMM in April of 2000 and current areas of responsibility include transactional service operations comprising of claims, EDI, configuration (both provider and benefits), eligibility and provider capitation. Prior to Operations, her focus was within Health Plan Contracting. Ms. Kamper earned her undergraduate degree from California State University of San Bernardino where she continued to receive her Master of Science in Health Services Administration in the year 2000.

Yvonne Sonnenberg, MHA, Associate Vice President, Network Operations and Executive Director, Empire Physicians Medical Group
Ms. Sonnenberg has over 20 years of experience in healthcare operations, previously holding positons responsible for general operations including managing networks consisting of over 190K managed care lives. She currently has oversight of Empire Physicians Medical Group, Mercy Physicians Medical Group, and Primary Care Associates. Ms. Sonnenberg has worked for both IPA and Staff Model HMOs in California directing Network Operations and Development, Contracting, Provider and Member Services, Transactional Services and Product Development. She has also worked as an adjunct professor, teaching management principles, and as a national healthcare consultant. Yvonne has been active with state and national healthcare associations for many years. She has served on numerous health care association boards and has participated in federal rule making with CMS. She currently serves as a board member and officer on the Industry Collaborative Effort for Healthcare Association, “ICE”. Ms. Sonnenberg holds a Bachelor of Science in Management and a Master’s degree in Health Care Administration.

Vera Grodzen, Associate Vice President, Network Operations
Ms. Grodzen joined NAMM California as AVP of Network Operations in Aug 2017. Vera’s regional responsibilities include oversight for PrimeCare Chino, PrimeCare of Inland Valley, PrimeCare of San Bernardino, and PrimeCare of Redlands. She has worked in managed care and medical group operations for the majority of her career. She joins us from Davita HealthCare Partners (DHCP) where she held various roles including accountability for medical group operations for the San Gabriel Valley. Ms. Grodzen earned her Bachelor of Science in Physiological Science from UCLA and a Masters degree in Health Administration from USC. Her background and operations experience will position her to contribute at a high level and will be valuable as NAMM’s business continues to evolve over the coming years.

Yvonne Muñoz, Associate Vice President, Network Operations
Ms. Muñoz is the AVP of Network Operations and joined NAMM California in June 2017. She earned her BA in Political Science from Regis University and her Juris Doctorate from Denver University College of Law. Prior to joining NAMM, Ms. Muñoz worked at Physician Health Partners (PHP) which is based in Denver, Colorado and her responsibilities included provider contracting, payer contracting, provider relations and network management, development of alternative product lines, and oversight of organizational compliance. Her background includes managed care and IPA management.

Unmesh Srivastava, Associate Vice President and Head of Innovation and Business Transformation
Mr. Srivastava joined NAMM California in February 2013. He has over 12 years’ experience in healthcare technology, strategy and innovation and has built multiple innovative technologies and processes for Population Health Management, Risk Adjustment, Quality Improgement, Medical Management, Network Management, Customer Service, and Marketing. Prior to joining NAMM, he worked as an Innovations Architect at Kaiser Permanente Southern California since 2009 and delivered multiple emerging technology initiatives in care delivery, health plan, pharmacy and labs space. He earned a Master's of Science in Manufacturing Systems and Engineering Management from California State University Northridge and a Bachelor's of Science degree in Engineering in Electronics and Communication from Rajasthan University, India. He is passionate about utilizing emerging technologies to support, enhance and disrupt care delivery and believes that technology can change the world.

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