National Casemix Office


The National Casemix Office (NCO) designs and refines classifications used to describe NHS healthcare activity in England. These classifications underpin the national reimbursement system from costing through to payment, and support local commissioning and performance management.

Top tasks

Download Groupers and Tools - download the latest HRG4+ Costing or Payment Groupers and the latest Prescribed Specialised Services Tool, along with supporting documents. Expected publication dates: 2017/18 Reference Costs Grouper and documentation suite - now published 19 March 2018. 2018/19 Updated Local Payment Grouper (no design change from 2017/18), updates to grouper usability only - now published 17 April 2018.

Our definitions, remit and deliverables - this page contains the science of casemix, the design framework and details of our stakeholder engagement, along with more information about casemix.

Casemix analytics - find additional information, including the clinical appraisals carried out on the Reference Costs collections which evaluate the performance of HRG4+.

Improving Access to Psychological Therapies (IAPT) Payment and Outcomes Tool - find out more about the Payment and Outcomes Tool that supports the Improving Access to Psychological Therapies (IAPT) payment model.

Casemix describes the mix of patients seen by a consultant, hospital or region, and how this patient care and treatment can then be classified into groups. These manageable groups provide a useful measure on which to make performance comparisons, to cost healthcare, or to fund it. Within the English NHS, these groupings are called Healthcare Resource Groups (HRGs) and are created and maintained by the NCO. 

The NCO are commissioned to create casemix currencies and the associated software to apply the design algorithms by NHS England. The HRGs provide a clinically-endorsed view of acute healthcare activities undertaken within the English NHS, which underpins both the National Reference Costs collection and the National Reimbursement System. The most current version is HRG4+. 

The NCO engages with more than 250 healthcare professionals via Expert Working Groups (EWGs) covering all clinical areas. The HRG designs are updated annually and represent clinical care, within the boundaries of available, nationally mandated data. The HRG4+ classification can acknowledge the additional resource use required when treating patients who:

  • have multiple complications and comorbidities that affect the clinical input for their care
  • require surgery at a very young age
  • require multiple procedures undertaken at the same time, within the same hospital admission or attendance
  • require surgery that utilises new devices, or innovation in the traditional clinical approach
  • require more complex care

Register for updates

Register for updates about the latest Grouper releases and casemix products. When a new Grouper product is released, you will be contacted via email.

Contact details

If you have a question about our Grouper products, please call 0300 303 5678 or email