The Department of Human Services' high-profile chief information officer Gary Sterrenberg will depart the agency next month after more than six years in the role, iTnews can reveal.

It leaves arguably the most technology-intensive leadership position - which involves looking after the IT operations of Centrelink and Medicare - across the federal government up for grabs.

Sterrenberg departs to work on a PhD, which he has been studying part time at the Australian National University, iTnews understands.

His PhD topic is listed as "measuring public value created through the introduction of a disruptive, digital platform-servicing model in the disability sector in Australia".

His official last day will be January 2, according to an internal memo sighted by iTnews.

The executive came to DHS in late 2011 from ANZ Bank, where he spent five years in various technology executive roles.

He walked into a department that was just four months into its new role as a “super-agency” made up of Centrelink, Medicare, and the Child Support Agency.

It had also just been told to cut operating and capital costs to help bring the Commonwealth's budget into surplus.

The directive came at about the halfway point for DHS' so-called service delivery reform (SDR) program, which involved the consolidation of data centres, IT systems and contracts.

Such big-bang projects characterised Sterrenberg's six years at the agency: from its 2012 SAP ERP consolidation, the ambitious delivery of myGov, to the more recent efforts to replace the mammoth systems that underpin Medicare and Centrelink.

The agency's IT shop has also spent the past few years dabbling in artificial intelligence and machine learning, deploying three virtual assistants in the space of a year.

Sterrenberg has also overseen the somewhat more contentious SAP-based overhaul of the child support payments system as well as the so-called 'robodebt' Centrelink automated debt notices and data matching program.

The department's head of IT infrastructure Mike Brett will act in the CIO role until January 14, at which point chief technology officer Charles McHardie will take over acting in the position while recruitment is underway.

DHS declined to provide further detail.