The Law Society says immigrants can be reassured over new legislation after safeguards were introduced to protect them.
The fast-tracked immigration bill passed its final hearings in Parliament on Friday.
About 350,000 people are in New Zealand on temporary visas and more than two-thirds of those are on work visas.
Some have lost their jobs and been unable to start new ones, others are overseas and worried whether their visas - and jobs - will still exist when the border re-opens.
In an email to stakeholders, Immigration New Zealand (INZ) said the Minister of Immigration had assured the migrant community in New Zealand that the government would not use the powers in the act to take away any existing visa rights.
It can now impose, vary or cancel conditions for groups of temporary entry class visa holders, extend expiry dates and stop some people offshore from making applications.
"These changes could include amending visa conditions for groups of people such as what region they can work in, or extending visa expiry dates for groups of people," it said.
"The new powers cannot be used to change conditions if that change would materially disadvantage the class of visa holders concerned.
"It is an effective safeguard because it means that the minister would not be able to use the powers in a way that materially deprives visa holders of existing visa rights (eg work rights)."
The legislation was a pragmatic solution to challenges it faced, it said.
"Several hundred thousand people on temporary entry class visas are in New Zealand at present - too many to easily deal with on an individual basis when the system is so disrupted."
The convenor of the Law Society's immigration and refugee committee, Mark Williams, was among those who made submissions to the Epidemic Response Committee on the bill.
He said that safeguards recommended by select committee MPs were incorporated into the bill.
"The bill in its previous form, we and other industry participants had concerns around the potential purpose it could be used for - and the wide ranging, very powerful discretion it gave to the minister to essentially make law, without going through the normal process.
"That's now been somewhat modified and balanced with the select committee hearings."
The legislation was designed to bring efficiencies to the system to quickly resolve delays and uncertainties, he said.
"With the additional safeguards that have been built into it, there is now a view that those powers can only really be exercised without material detriment to the migrants concerned.
"I think it will clarify a lot of the questions or uncertainty about what's happening with [visa] processing.
"There's been a lack of information flowing and those questions around people, can they come in - 'I've got a visa expiring offshore and I've got to get in in the next three weeks when is that going to happen?'
"I think the powers bestowed on the minister will help answer a lot of those questions and help reset or extend a lot of those entry times, so it should give far more certainty to some people and ease some of the stress on those visa holders."