Luigi Mangione Not on Suicide Watch at Pennsylvania Jail

Luigi Mangione's not on suicide watch after being examined by mental health professionals ... TMZ has learned.

A representative for the Pennsylvania Department of Corrections says ... the man accused of killing UnitedHealthcare CEO Brian Thompson isn't currently under any psychiatric order at SCI Huntingdon, a correctional facility just outside Altoona.

We're told he was evaluated by medical and psychology professionals as part of the regular screening ... and, no psych order was put in place.

As we told you ... Mangione is locked up in a single cell and won't have any interaction with other inmates, for now.

We're told he's not in solitary confinement, and he will eventually be let out of his cell ... a privilege all inmates have -- even those with a higher custody level.

Mangione's been charged in PA with forgery, tampering, presenting false ID to law enforcement, and carrying a firearm without a license.

In New York City, he's facing a second-degree murder charge ... Mangione is currently fighting extradition to New York.