President Barack Obama is clearing the way for families of US hostages to pay ransom to terror groups without fear of prosecution.
The move comes as the White House seeks to address criticism from those whose loved ones have been killed in captivity.
The hostage policy review to be released today will also state that the US government can help facilitate communications with terrorists on behalf of the families.
However, a prohibition on the government directly paying ransoms or making other concessions to terrorists will remain in place.
Mr Obama will speak about the policies shortly after meeting the families of Americans who have been held captive.
The president ordered the review last year after families complained about their dealings with the administration, saying they were threatened with criminal prosecution if they pursued paying ransom in exchange for their loved ones' release.
There will be no formal change to the law that explicitly makes it a crime to provide money or other material support to terror organisations. However, the administration will make clear the justice department has never prosecuted anyone for paying ransom and that will continue to be the case.
While the government has long turned a blind eye to family contacts with terrorists, officials acknowledge the unspoken policy has been applied unevenly. The inconsistencies have been magnified in recent months with the kidnappings and killings of Americans by terror groups.
Four Americans have been killed by Islamic State (IS) since last summer - journalists James Foley and Steven Sotloff and aid workers Peter Kassig and Kayla Mueller.
After the release of gruesome videos showing the beheadings of some hostages, Mr Obama approved an airstrike campaign against IS in both Iraq and Syria.
The families' anguish has been deepened by the fact that European governments routinely pay ransom for hostages and win their release.
The US says its prohibitions against the government and private individuals making any concessions to terrorist demands are aimed both at preventing more kidnappings and blocking more income for terror groups.
However, the Obama administration did negotiate with the Taliban last year to win the release of Army Sgt Bowe Bergdahl, who was captured after walking away from his post in Afghanistan. Five Guantanamo Bay detainees were exchanged as a condition of his release.
White House officials say those negotiations were permissible because Mr Obama sees a special responsibility to leave no American service member behind on the battlefield.
Elaine Weinstein, whose husband Warren Weinstein was accidentally killed by a US drone strike in April while being held hostage by al-Qaida, argued against the government making such distinctions between US citizens.
"The people who take American citizens working abroad as hostages do not discriminate based on their job or employer, and neither should our government," she said.
Even as the administration eases restrictions on families, officials said the ban on the US government directly paying ransom or making other concessions to terrorists would remain.
"The president does continue to believe that it's important for the United States of America to adhere to a no-concessions policy," White House spokesman Josh Earnest said.
The White House invited the families of 82 Americans held hostage since 2001 to participate in the review, and 24 agreed to do so. The national counterterrorism centre, which oversaw the review, also consulted with hostage experts from the US and other countries.
As part of the review's findings, Mr Obama will announce the creation of a hostage recovery "fusion cell" at the FBI that will co-ordinate the multiple government agencies involved in such issues.
The new office aims to address family frustrations about getting contradictory information from different agencies by creating a single point of contact.
"We had no one accountable for Jim," Diane Foley, the mother of James Foley, said earlier this year. The Foley family has also said the government uses its policy of not paying ransom or negotiating with terrorists to avoid answering families' questions.
Mr Obama is also expected to announce the creation of a state department special envoy post that will head the administration's dealings with foreign governments on hostage matters.