The Greens are expected to use senate estimates on Tuesday to press officials and the Albanese government about HMAS Stirling in Western Australia being classed as a US shore installation.
A US government procurement site has since April referred to the base as Naval Support Activity Stirling.
Bases located in the US and across the world are referred to as "naval support activity".
US War Secretary Pete Hegseth told a major defence summit in Singapore at the weekend he had authorised the establishment of naval support activity Stirling submarine squadron three, which will result in the first American sailors arriving in WA later this year.
He praised Australia's commitment to spend up to $8 billion to upgrade HMAS Stirling's infrastructure.
Under AUKUS, the Australian military is set to acquire three Virginia-class submarines in the early 2030s, before a new fleet is built for delivery from the 2040s.
Greens defence spokesman David Shoebridge will grill officials about how taxpayers will pay for infrastructure, in addition to an announcement Australia will no longer buy new nuclear-powered submarines from the US.
Under the original plan, Australia was expected to receive one new Virginia class vessel, in addition to two used ones.
Opposition defence spokesman James Paterson has said he would ask questions about the change during the parliamentary hearings this week.
A last-minute reduction in scope to the "life-of-type extension" plan for the Australian navy's Collins class submarines will also be probed.
A damning audit of the project found as of February, $693 million had been spent on design-related work before the government announced in May a new direction would be taken.
The Department of Veterans' Affairs is expected to face questioning over the new $5000 annual limit on allied health services for veterans, introduced in a bid to stop overcharging of services.
The terms of reference for the inquiry into military sexual violence, released on Monday, will also likely be scrutinised.
Veterans' Affairs Minister Matt Keogh said the federal budget in May had committed $16.6 million in funding for the probe.
"Importantly this inquiry will recommend systemic improvements as we work to eradicate the scourge of sexual violence in the Australian Defence Force," he said.
The standalone investigation was recommended by the Royal Commission into Defence and Veteran Suicide.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
Lifeline 13 11 14
beyondblue 1300 22 4636
