He said older people, aged care facility residents, disability care residents aged 16 years and over, and severely immunocompromised people aged 16 years and over could be eligible.
"Final decisions on the make-up of this group will be made within the next two weeks," he added.
The Government wanted second boosters to be available without needing to access a GP.
"This will be more equitable and make the roll-out to our at-risk groups more effective," Hipkins added.
"We intend do this by amending the Medicines Act, and anticipate the new policy will be in effect from mid June, in good time for the vast majority of eligible people."