WASHINGTON (AP) — The Supreme Court ruled unanimously Monday that low-level crack cocaine offenders convicted more than a decade ago can't take advantage of a 2018 federal law to seek reduced prison time.

The justices affirmed the nearly 16-year prison term handed out to Tarahrick Terry of Florida, who was arrested with 3.9 grams of crack on him in 2008.

Terry's case concerned the reach of the First Step Act, a bipartisan 2018 law signed by former President Donald Trump. Aimed at reducing racial disparities in sentencing, the law allows prisoners convicted of older crack crimes to seek reduced sentences.

But the law specifically addresses crack possession only above 5 grams for one category of possession and above 50 grams for another category.

That allowed crack cocaine kingpins to seek reduced sentences, but it left convicts like Terry in a legal limbo, with courts around the country coming to different conclusions.

In an opinion by Justice Clarence Thomas, the high court said Terry and those like him who were not subject to a mandatory prison term based on how much crack they possessed are out of luck.

"The question here is whether crack offenders who did not trigger a mandatory minimum qualify. They do not," Thomas wrote.

Terry is in the final months of his prison term. And he apparently is serving his remaining time on home confinement, according to the Biden administration.

The outcome probably affects no more than a couple hundred prison inmates since most people convicted of possessing relatively little crack that long ago already have finished serving their sentences.

The 2018 law, like the Fair Sentencing Act of 2010, was partly aimed at addressing disparities, which fell disproportionately hard on Black people, in the treatment of people convicted of crack and powder cocaine offenses.

The case only affects people whose crimes took place before August 2010 because the Fair Sentencing Act took effect then and covered crimes committed from that point forward.

The Trump administration had argued that Terry is not eligible to seek a sentence reduction, but the Biden administration changed course.