[smj-edison]

To be precise, the treasury prints the bills, not the federal reserve. The federal reserve balances what money is in circulation by selling or buying bonds. When they issue a bond, someone buys it, so money is removed from circulation. When they buy a bond, money is injected into circulation.

[lxgr]

It’s the other way around. The treasury issues bonds; the Fed buys (or repos) them in exchange for newly issued USD.

[smj-edison]

Oh whoops, you're right!