On 1 April 2019, the National Institute for Health and Care Excellence was 20 years old. This is an anniversary worth noting, if for no other reason than how remarkable it is for a National Health Service quango (quasi-autonomous non-governmental organisation) to be still standing two decades after its inception. There are more reasons for marking and celebrating the National Institute for Health and Care Excellence’s 20-year run. In the intervening years, the Institute has done much to advance the health of the UK population. It has achieved an international reputation for robust and fair healthcare prioritisation that is widely viewed as setting the global standard. The National Institute for Health and Care Excellence built this reputation not only through the rigorous development and application of scientific methods to guide its work but also through its efforts to articulate the underpinning social and ethical values that provide its decisions with robust justification. The National Institute for Health and Care Excellence’s reputation also rests on its commitment to transparency, accountability and inclusiveness in facilitating public and patient input in its deliberations.