MSN began as a successful radiology group’s billing department and progressively evolved to become one of the leading radiology billing companies in the nation. We understand the operational culture and needs of the radiology practice and carefully assembled a team of experienced billing experts, supported by leading industry technology. We speak the language of radiology and are totally committed to the success of our clients.

MSN also invested in infrastructure, beginning with installation of a leading billing software in 2005, which encouraged a culture of continuous process improvement and the use of intelligent automation.  


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Walt Blackham
Senior Vice President Coding & Client Services

Walt has a strong background in radiology billing and practice management and is recognized nationally as one of the leading authorities on radiology coding. Walt has been practice administrator of a large radiology group practice for more than 20 years and formerly President and CEO of Specialty Medical Services, Inc., a billing service for radiology and pathology practices.

He has served as Chair of the RBMA Coding Committee and is currently a member of the Committee on Coding and Nomenclature of the American College of Radiology (ACR), a position he has held intermittently for many years.

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Karl Brown
Senior Vice President of Client Services

Karl brings more than twenty years of experience to his role as Senior Vice President of Client Services and provides practice management and strategic support for MSN clients.  He is a graduate of Auburn University and active member of the RBMA on both a national and state chapter basis.  In addition, Karl is Vice President of Human Resources for MSN and in that role, is responsible for developing employment policies, benefits design and corporate infrastructure.  

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Renée Engle
FRBMA & Senior Vice President of Client Services

Renée Engle offers extensive experience in CPT/ICD coding, MIPS and healthcare management.  She also acquired a background in nursing and credentials as a Radiology Certified Coder (RCC) and Radiology Certified Coder in Interventional Radiology (RCCIR.)

She joined MSN in 1997, overseeing client services and providing guidance on dictation and compliant documentation for MSN physician clients, including customized educational programs for specific client areas of interest.

Renee is President of the Radiology Coding Certification Board (RCCB) and is a member of the American College of Radiology (ACR) CPT and Nomenclature Committee and the ACR Carrier Advisory Committee (CAC), where she has served for several years. A Fellow of the RBMA, she also served as an At-Large Director on the RBMA Board and as President of the Georgia RBMA.      

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Debbie Harmon
Senior Vice President of Operations, Western Region

Debbie has worked with MSN since 2009 and leads the MSN offices in Colorado and Arizona, providing services to clients in the Western RegionWith more than 20 years of experience managing billing and coding operations, she has a strong working knowledge in all process areas of the revenue cycle and offers her clients the benefit of hands-on experience and expertise.

Debbie is a Certified Healthcare Billing Management Executive (“CHBME”) through the Healthcare Billing and Management Association (“HBMA”). She has also served on the HBMA Board of Directors and was President of the Colorado chapter of the RBMA.  

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Susan Gregg
Senior Vice President

Susan joined MSN 2015 and brings more than 35 years of radiology practice management experience to her clients.  Prior to joining MSN, Susan was a principal in Shared Management Services, a revenue cycle management company.  Susan has been an active member of the RBMA, earning fellowship distinction in 2011.  She has held leadership positions on both the national and state level and served as the RBMA’s National President.  She currently serves on the ACR Managed Care and Payers Relations Networks, the Oklahoma Medicare Contractor Advisory Committee, and the Medicare Provider Outreach and Education Advisory Group.  Susan is Immediate Past President of the Radiology Coding Certification Board and iscertified as a Medical Practice Executive by the American College of Medical Practice Executives.

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Suzanne B. Taylor
Senior Vice President of Operations Central Region

Suzanne contributes a strong background in medical practice management, accounting and billing to MSN clients, a career that began in 1985. She joined MSN in 2008 and is an excellent resource to clients, providing operational oversight, workflow analysis, personnel management and client services to groups in MSN’s Central Region.

Suzanne served as President of the RBMA and was named a Fellow in 2010 as part of that organization’s inaugural Fellowship class.  In addition, she was Chair of the Managed Care Task Force, Nominations Committee and Fellowship Selection Committee. Suzanne continues to serve on the RBMA Federal Affairs and Payer Relations Committees.


  • Experienced certified radiology (RCC) and interventional radiology (RCCIR) coders 
  • Coding from physician reports 
  • Physician education: documentation, medical necessity and compliance 
  • Charge acquisition and verification 
  • Fee schedule analysis and recommendations 
  • Responsive claims follow-up and appeals 
  • Monitoring of accounts receivable trends 
  • Workers’ Compensation expertise 
  • Data entry 
  • Refund reconciliation of overpayments 
  • High level of accurate claims submission
  • Streamlined appeals processes
  • Flexible billing cycles
  • Patient payment plans
  • Payment plans
  • Payment options

    • Phone
    • Portal
    • Mail
    • E-chat
  • Complete and detailed billing management reports
  • Flexible and responsive reporting and analysis