Terrence Howard just got hit with a fat tax bill that he now has to pay back to Uncle Sam -- after ignoring a federal complaint against him ... a judge just ruled he's gotta pay up. The actor was ordered to pay close to $1 million Friday in a federal tax evasion case out of Pennsylvania that he's been wrapped up in since last year -- when the feds came after him for what they claimed were hundreds of thousands of dollars in back taxes he owed. Specifically, they were attempting to recoup a huge tab from him in the amount of $578,000 -- amounting to a huge tax bill they claimed had gone unpaid from 5 tax returns between 2010 and 2019. And now, all this time later ... they finally got a federal judge to throw down the gavel in their favor. The weird thing ... it looks like Terrence blew all this off. Waiting for your permission to load the Instagram Media. According to the legal doc, obtained by TMZ, the court notes Terrence failed to appear or otherwise defend himself at all in this case. That's odd ... 'cause he's somewhat active on social media -- posting promotional stuff for projects he's involved in, etc. As a result ... he's now technically on the hook for $903,114.72. This whopping amount covers the unpaid federal tax income assessments, penalties and interest accrued. We've reached out to Terrence ... so far, no word back.