Apparently so. One of their "journalists", former Trump henchman Steve Cortes, is resigning his short-lived position at the the propaganda outlet because they are complying with the Biden administration vaccine mandate. (This seems unusual because I thought a court decision had derailed the mandate, but maybe it's under appeal.)
"The veteran news pundit had voiced on social media his discontent with Newsmax's requirement of proof of vaccination, which followed President Joe Biden's executive order forcing companies with 100 or more employees to obtain proof of vaccination from their workers or subject them to weekly testing and masking."
I'm surprised that Newsmax is actually complying and not putting up some kind of symbolic protest or something like that.
Here's some clarification (but note that this is from November 9).
Newsmax tries to assuage furor of conservative hosts over vaccine mandate