oil spill has called for wide-ranging reforms of the oil industry to prevent a repeat of the disaster.
The report comes from a US presidential commission investigating the spill.
The panel also said the US needed to expand and update drilling regulation and establish an independent drilling safety agency.
The April blast aboard the Deepwater Horizon rig killed 11 people and caused one of the worst oil spills in history.
The Macondo well, about a mile under the sea’s surface, eventually leaked millions of gallons of oil into the Gulf, damaging hundreds of miles of coastline before it was capped in July.
The findings came in the final report of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, which President Barack Obama convened in May to investigate the root causes of the spill and recommend changes to industry and government policy.
The report spreads blame for the disaster widely, criticising BP, which owned the Macondo well; Transocean, which owned the rig; and Halliburton, which managed the well-sealing operation.
It said the companies had cut corners to save time and money – decisions that contributed to the disaster.
It also takes aim at the US federal government, finding that regulation and legislation governing off-shore oil drilling failed adequately to protect oil workers and residents of the environmentally-fragile Gulf coast.