Treasury secretary Martin Parkinson says he never got a sense from Treasurer Joe Hockey that he was no longer required in his role under the new government.
Dr Parkinson is due to stand down as Treasury secretary in the middle of next year after assisting Mr Hockey with his first May budget.
His resignation was announced by Prime Minister Tony Abbott shortly after Mr Abbott was sworn in on September 18, saying it was Dr Parkinson's decision to leave the role early.
However, there was speculation Dr Parkinson was pushed because the announcement coincided with the sacking of three other heads of department.
Asked about this during a Senate hearing, Dr Parkinson said he had only spoken to Mr Hockey about his position, which he had held since March 2011.
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"By the latter part of next year I would have been a secretary for seven years," Dr Parkinson told the estimates hearing in Canberra on Wednesday.
"I will be 56. There's a lot of things in life that one could do, notwithstanding this is probably the best job one could have, without a doubt, in government, and pretty broadly beyond that."
Dr Parkinson had previously been the secretary for the Department of Climate Change.
Mr Abbott has said he would discuss a further appointment for Dr Parkinson next year.
But Dr Parkinson denied speculation he would become Australia's executive director at the International Monetary Fund based in Washington.
"It's a fine job for people who would like to go and do that. I'm not going to Washington to do that role," he said.
"It hasn't been raised with me.
"Were it to be raised with me, that would be my answer, and the reason is if you look at my history I actually spent four years at the IMF."
Assistant treasurer Arthur Sinodinos told the hearing Dr Parkinson had handled the transition under the new government "very well, very professionally and retains our full confidence".
