As defined by Stout and Overton, HPEMS systems share key features of system design rarely associated with less cost-effective systems with examples as follows:

• Sole provider: Exclusive market rights to furnish emergency and non-emergency ambulance service are granted to a sole and often competitively selected provider for a specific population or service area.
  
• Control center operations: The ambulance provider has control of the dispatch center.
  
• Accountability: HPEMS systems have performance requirements that can result in financial penalties or replacement of the provider when the requirements are not met. HPEMS systems use and collect data regularly to meet these performance requirements, which has allowed for the ability to collect data for the HPEMS Market Study.
  
• Revenue maximization: HPEMS systems incorporate the business function into their operations, with the resulting understanding of the billing requirements and maximization of revenues from Medicare, Medicaid, and other third-party payors.
  
• Flexible production strategy: HPEMS systems employ a single fleet of ALS units capable of handling any type of service request, resulting in all patients receiving the highest level of care and higher productivity levels.
  
• System Status Management (SSM): HPEMS systems use the flexible deployment technique, SSM, to move ambulances in anticipation of where that ambulance will be needed.