When Martin Bowles looks back at his long public service career, he likes to think he was able to achieve that. Indeed it was always at the centre of his mind.

"You tell truth to power," he said.

Mr Bowles led high profile departments in politically tumultuous times and said being able to provide brave policy advice - no matter how it may be perceived by the public, politicians or the media - was one of the greatest challenges of public work.

His 40-year public service career saw him lead the Immigration Department from 2011-14 and the Health Department from 2014-17.

He was on Monday named an officer of the Order of Australia for his long service to public administration and policy.

He said the award was an honour and unexpected. "It's a really nice feeling that you think, maybe you have actually done some good work," he said.

He's now the national chief executive of Calvary Health Care, working in Sydney during the week, but returning home to Canberra on the weekend.

Part of that role has been forging better relations between Calvary Public Hospital in Canberra and the ACT heath directorate, one he concedes was rocky not too long ago.

Mr Bowles said Australia needed to be able to have more robust policy discussions and public servants needed to be able to provide sound advice even if it was likely to lead to backlash.

"[Policy advice] should keep the community absolutely in focus - that's always a challenge and is getting more and more difficult with policy ideas," Mr Bowles said. "Sometimes they are difficult to explain and sometimes they are difficult to deal with.

"You've got to have the Australian community at the centre of you attention."

Mr Bowles said his time in immigration was one of the most polarising areas he had worked in.

He oversaw the department at a time of great scrutiny, especially regarding the issue of children in offshore detention.

He said he worked hard to protect the organisation and his colleagues from at times intense criticism.

"That work in immigration was always very difficult - it can be a very polarising but you have to do things that make a difference," he said.

While he was secretary of that department during two different governments, he said sometimes a change of minister actually provided the most uncertainty.

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"There was a change of government in the middle of my term and I think everyone came out OK," he said.

"A lot of the time of course you don't know it's going to change, you have to prepare for all sorts of alternatives."

Mr Bowles left the public service in 2017 and now heads Calvary Health care - a not for profit Catholic health organisation.

Calvary runs four public hospitals across the country, including one in Canberra.

It has a further 11 private hospitals that provide acute and sub acute services.

"The transition [from the public service] was not that hard because my values set was very similar to that of the organisation," he said. "You do need to learn some new language and change the way you deal with some things."

While Calvary's relationship with Canberra Hospital and the health directorate has not always been smooth sailing, Mr Bowles said that had changed in the past 12 to 18 months.

"[Our relationship] has dramatically improved," he said.

"I talk regularly to the minister and Michael De'Ath (director general of the ACT Health Directorate).

"If I look around the country, good working relationships with government mixing public and private health services are essential.

"Canberra is a good example and we've got very good relationships these days."