NHS England has a range of initiatives to support improved efficiency in the National Health Service, including an initiative to ensure that HIV services are prescribing the lowest cost, clinically appropriate anti-retroviral drug options available. This initiative has been developed and led by HIV clinical experts and patient representatives. Based on advice about clinically appropriate treatment options, NHS England has calculated that this initiative is likely to deliver overall a 2.5% efficiency on the cost of antiretroviral drugs during 2016/17 and 2017/18. NHS England will monitor whether clinical practice matches these assumptions. The assumption for 2017/18 is that this initiative will deliver savings of £24 million. Assumptions for 2018/19 are not yet available. Regional breakdowns have not been published.