Judge Steven Rhodes issued a brief order Monday, saying he'll rule from the bench at 9 a.m. Eastern Time on Dec. 3. He said he'll issue a written decision later.
Lawyers for Detroit and its creditors aren't required to attend. Appeals are likely.
Rhodes presided over a nine-day trial that ended Nov. 8. Unions and pensions funds claim Detroit isn't eligible for bankruptcy because it failed to hold good-faith negotiations before the filing. The city says it did enough.
A decision in favour of eligibility would mean the case would turn to how Detroit can fix $18 billion in debt.