The findings were published on Tuesday following a 13-year process examining hundreds of complaints and conduct matters linked to the disaster.
The report concludes that 12 former officers would have faced gross misconduct proceedings had they still been serving.
A thirteenth would have faced a lesser misconduct case. Investigators determined that critical operational decisions by police on the day directly contributed to the crush on the Leppings Lane terrace, which resulted in the deaths of 97 people.
The report reiterates that supporters were not to blame.
According to the findings, police planning for the match at Hillsborough was inadequate and marked by an absence of proper risk assessment.
On the day, officers failed to recognise the developing danger inside the central pens and did not take appropriate steps to relieve pressure. The report states that these failures had catastrophic consequences.
The investigation also found that police attempted to deflect responsibility in the aftermath. The report confirms widespread alteration of officers' statements, noting that substantial changes were made to remove criticisms of policing.
It adds that misleading narratives about supporter behaviour were circulated despite no evidence supporting claims of drunkenness, ticketlessness or disorder.
Bereaved families and survivors, who have spent decades challenging the original account of events, said the findings validate what they have consistently argued.
Lack of accountability
Many expressed frustration, however, that no disciplinary action can now be taken because all named officers have retired.
The report notes that current regulations do not allow retrospective misconduct proceedings for former officers in these circumstances.
The findings follow the 2016 inquests, which concluded that the 97 victims were unlawfully killed and that the behaviour of supporters did not contribute to the disaster.
Only former Sheffield Wednesday Football Club secretary Graham Mackrell was ever convicted over the disaster.
The new report reinforces those determinations and highlights repeated institutional failures both before and after the tragedy.
The IOPC described the families' decades-long pursuit of truth as a demonstration of extraordinary resolve.
The report emphasises the importance of candour from public bodies and suggests that earlier transparency would have prevented years of avoidable distress.
The publication marks one of the final major investigations into the disaster, providing the clearest official account to date of the policing failures that led to Britain's worst stadium tragedy.