The hearing, scheduled for 11:30 a.m., is expected to focus on plans for trial, including proposed juror questionnaires, jury selection and scheduling matters.
The hearing comes after sources familiar with the matter told ABC News that federal prosecutors and Mangione's defense attorneys discussed a possible guilty plea ahead of Monday's court appearance. Sources said it was unclear how close the two sides came to reaching an agreement before negotiations stopped.
Mangione's legal team has denied those reports.
"This information attributed to 'anonymous sources' is part of a troubling, deliberate pattern by prosecutors and law enforcement to prejudice Luigi, manipulate public opinion, and violate his constitutional right to a fair trial and impartial jury," lead defense attorney Karen Friedman Agnifilo said in a statement.
"Every defendant in America is presumed innocent until proven guilty, including Luigi, who, unlike any other defendant, has to fight the same charges twice," she added.
Mangione, 28, has pleaded not guilty to both state and federal charges stemming from the December 2024 fatal shooting of UnitedHealthcare CEO Brian Thompson outside a Midtown Manhattan hotel.
The case has drawn worldwide attention, with supporters continuing to gather outside the courthouse during hearings.
Mangione's state trial is currently scheduled to begin Sept. 8, while his federal trial is expected next year.
ABC News contributed to this report.