This has been the best article I can find on MMT. It’s very long, but the most relevant part to your question is this:
The QE model can create a synthetic version of MMT if the government and Federal Reserve work closely together, which is what is happening now. My previous example of the Treasury sending out helicopter checks to people that are ultimately paid for by issuing Treasuries that the Federal Reserve buys with newly-created dollars (with primary dealer banks as intermediaries), is basically MMT in practice. In other words, what people think of as MMT can essentially be done in the current legal framework.
However, although QE creates new dollars out of thin air, the process still goes through the motions of pretending to respectfully treat money in the same way it was treated in the first two models, meaning something that has to be borrowed from somewhere before spent, and balanced by an asset on the other side (a Treasury security that gets locked away on a central bank balance sheet in place of newly-created dollars, forever to be rolled to the next one when it matures). For a while, those motions along with statements by officials provided many investors reasons to believe that maybe newly-created dollars would be paid back, maybe the Federal Reserve will be able to reduce their balance sheet, and so forth. Those beliefs proved to be unrealistic, but the realization that it was debt monetization is only coming years later for many people after the temporary nature of it proved permanent when quantitative tightening failed in 2019.
MMT, on the other hand, drops a lot of those pretenses of QE and just treats money as something that can be printed whenever unused economic capacity exists. It’s not that fundamentally different than QE; it just cuts to the heart of it and removes some of the steps.
In 2020, Congress has been showing us — in practice if not in its rhetoric — exactly how M.M.T. works: It committed trillions of dollars this spring that in the conventional economic sense it did not “have.” It didn’t raise taxes or borrow from China to come up with dollars to support our ailing economy. Instead, lawmakers simply voted to pass spending bills, which effectively ordered up trillions of dollars from the government’s bank, the Federal Reserve. In reality, that’s how all government spending is paid for.
This has been the best article I can find on MMT. It’s very long, but the most relevant part to your question is this:
And here’s a confirmation from a prominent proponent of MMT: