Brian Foster was released from prison nearly a year ago under the CARES Act, a government policy that prioritized the use of home confinement as an appropriate way to release some incarcerated people as Covid-19 roared through facilities. When Foster, 54, returned home to Atlanta, the first thing he did was surprise his mother. He moved in with two of his daughters, got a job as an auto mechanic tech, established credit and bought a grill so he can barbecue for his grandchildren, family and friends. His future, though, is uncertain. Foster is one of about 4,500 people on home confinement facing the possibility of being returned to prison once the pandemic recedes. The Federal Bureau of Prisons website said it "significantly increased its placement of offenders on home confinement" after then-Attorney General William Barr issued a memo in March 2020 directing the bureau to prioritize releasing inmates who were deemed to have especially serious health issues that put them at higher risk for severe illness caused by Covid-19. But later, in the waning days of the Trump administration, the president issued a memo that said federal offenders with sentences lasting beyond the "pandemic emergency period" would have to return to prison. "It upsets me to be home doing all the right things and now they talk about I may go back," said Paulette Martin, 74, who lives with her son and his family in West Virginia. Dozens of advocacy groups have called upon President Joe Biden to exercise his broad presidential powers and commute the inmates' sentences. But the administration said its legal team interprets the Trump memo to mean people will be required to return to prison a month after the official state of emergency for the pandemic ends. In an email to NBC News, a BOP spokesman said the bureau may choose to keep inmates on home confinement post-pandemic if their sentence is nearly over. As for "more difficult cases," in which inmates have many more years to serve, "the BOP is focused right now on the expanded criteria for home confinement and taking steps to ensure individualized review of more inmates who might be transferred," the spokesman said. Still, thousands are waiting to learn about their sentences after the pandemic. "The Biden administration came in and we hoped this would be something they would overturn," Scott Roberts, senior director of criminal justice campaigns at Color of Change.