It means he'll be walking away from more than 883,000 performance rights — worth an astounding A$21.7m.
In the year to September 2018, Thorburn was paid A$4.3m.
According to the Australian Financial Review, acting CEO Phil Chronican, who will take Thorburn's place on March 1 until a permanent replacement is found, will be paid far less at A$150,000 per month, or A$1.8m a year.
Both Thorburn and Henry had been under intense scrutiny after Commissioner Hayne wrote in his final report he was not confident they had learnt any lessons from the landmark inquiry into the banking sector.
"More particularly, I was not persuaded that NAB is willing to accept the necessary responsibility for deciding, for itself, what is the right thing to do, and then having its staff act accordingly," he wrote.
"Overall, my fear — that there may be a wide gap between the public face NAB seeks to show and what it does in practice — remains."
NAB has also revealed Dr Henry will be barred from participating in the recruitment of Thorburn's replacement after his initial involvement in the selection process drew sharp criticism.
Instead, a CEO selection panel fronted by director Ann Sherry, and a chairman selection committee, headed up by NAB director David Armstrong, will take over.
There has been widespread speculation former NSW premier and current NAB consumer bank boss Mike Baird is a frontrunner for the position.
Thorburn, who served as chief executive since August 2014, released a brief statement earlier this month explaining he had decided to step down after conversations with the chairman.
"I acknowledge that the bank has sustained damage as a result of its past practices and comments in the royal commission's final report about them," he said.
"AS CEO, I understand accountability."
Thorburn was also rocked last year by allegations an employee he considered a friend had been involved in a multimillion-dollar fraud against the lender.
He also copped criticism after taking two months' leave over Christmas, with many accusing him of lacking the nerve to face the then-pending findings of the royal commission.
"I've got a marriage, I've got children I've got elderly parents: they're the people who I want to spend some time with," Thorburn said at the time.
"I think that it is important for mental and physical health to lead in a sustainable and long-term way; I want to role model to people inside the company that that's OK to do."