The government could build a new hospital in the city's north as an alternative to expanding Calvary Public Hospital.
But Health Minister Rachel Stephen-Smith has rejected suggestions it could mean Calvary would be left to "wither on the vine".
Building new northside healthcare facilities is part of the government's long term infrastructure plan, with a scoping study due to be completed next year.
Most conversations about these new services have focused on a redevelopment of Calvary Bruce Public Hospital.
But the government says it is also considering whether to build an entirely new hospital at a new site.
"I think if we need to look at a redevelopment option then we need to look at a greenfield option too if only for comparison on cost," executive group manager of strategic infrastructure at ACT Health Liz Lopa told annual report hearings on Monday.
She said the cost benefit of three options would be presented to government: building a new hospital at a new site, a complete redevelopment of Calvary, and refurbishing some buildings at Calvary while adding some new ones.
Ms Lopa said a full assessment report of all buildings at Calvary was being completed. That report would give the government an indication of whether a complete rebuild was needed or if it could be redeveloped.
Opposition health spokeswoman Vicki Dunne asked whether a potential new hospital would be an additional acute facility, or if Calvary would simply be left to "wither on the vine".
"We wouldn't use that language," Ms Stephen-Smith said. She said the government was in constructive discussions with Calvary about their continued provision of services.
"They are a very valued partner in our public health system," she said.
"In order to understand all the implications and ensure we are using taxpayers' money most appropriately we need to understand all the options that are available to us. But that work is being done entirely in partnership with Calvary and with an open conversation with them about the options that are being explored."
Ms Lopa said there was no site in mind for a greenfield hospital, but one would have to be chosen if a proper comparison of the options was provided to government.
"The options we're looking at are not going into who runs the hospital. It's really just how much it would cost you to build a hospital of a certain scope in a certain location," she said.
It is expected options from the scoping study on future northside hospital services will be given to the government for consideration by mid next year.
The scoping study was a 2016 election promise from Labor.
Calvary Bruce Public Hospital is government owned but privately managed facility.
A submission paper presented to the ACT government last year from Calvary said most of the hospital's buildings and infrastructure were rapidly reaching end of their useful life.
It said about $109 million over five years was needed to avoid further deterioration of ailing assets and to address performance gaps.
It said three quarters of critical and high priority buildings at Calvary public had condition ratings below target.