Penelope Schofield, the West Sussex coroner, said there was “institutionalised abuse” at the Orchid View care home in Copthorne.
She said those involved in the neglect of pensioners at the now defunct home should be “ashamed” as it was announced a serious case review has been set up.
A five-week inquest heard how some residents were given wrong doses of medication and left soiled and unattended due to staff shortages.
Call bells were also often not answered for long periods or could not be reached by elderly people living at the home, which was deemed “an accident waiting to happen”.
Ms Schofield said: “There was institutionalised abuse throughout the home and it started, in my view, at a very early stage, and nobody did anything about it.
“This, to me, was from the top down. It was completely mismanaged and understaffed and failed to provide a safe environment for residents.”
Ms Schofield said it was “disgraceful” that the home was allowed to be run in the way it was. She criticised the Care Quality Commission which gave Orchid View a “good” rating in 2010 – a year before it shut.
Speaking outside the inquest, former Orchid View administrator Lisa Martin, who first informed police of the problems at the care home, said she felt she had no choice but to come forward. “I had witnessed too much poor management and care to vulnerable adults and I couldn’t live with the knowledge any longer,” she said.
“Morally I know I did the right thing but personally I have not worked for two years and the case has had a huge impact on my life.”
The coroner said 19 residents at Orchid View suffered “sub-optimal” care. All of them died from natural causes, she ruled.
But five of those died from natural causes “which had been attributed to by neglect”, Ms Schofield ruled. They were Wilfred Gardner, 85, Margaret Tucker, 77, Enid Trodden, 86, John Holmes, 85, and Jean Halfpenny, 77.
The inquest heard that Mrs Halfpenny was overdosed on the blood-thinning drug warfarin while at Orchid View. Whistleblower Ms Martin said she was asked to shred forms after Mrs Halfpenny was admitted to hospital for bleeding.
Five people were arrested, including some on suspicion of manslaughter by gross negligence in relation to Mrs Halfpenny’s death, but insufficient evidence existed to support a prosecution and the case was passed to the coroner.