The Lammy Review (2017) examined the treatment by the criminal justice system of people from Black, Asian and Minority Ethnic groups.1 The Government accepted all 11 recommendations concerning prisons.2 It published an update on progress in 2020 but has declined to do so since. So in late 2022, the Prison Reform Trust gathered evidence to determine whether policies had changed to meet the recommendations, and – crucially – whether outcomes had improved (impact). In line with Lammy’s emphasis on the need for increased transparency, we have relied only on evidence in the public domain.