The federal reserve says it's been printing money every year but it's a lie. You can not produce one bill any denomination that's dated newer than 2017.
https://www.federalreserve.gov/paymentsystems/coin_calprint.htm
Remember that the dates on US paper money aren’t like dates on coins. Rather than indicating the year a bill was printed, it’s what’s called a “series date” that indicates when a particular version of the bill was created.
The rules are a bit loose, but in general a series date is changed only when (a) there’s a significant design change or (b) a new Treasury Secretary takes office. Neither of those events happened in 2019 so bills with the 2017 series date continued to be printed.
The situation with expected 2021 series bills is a bit more complicated than usual. As you can see by looking at any bill in your wallet they also carry the signature of the US Treasurer. When a new administration takes office printing of new bills can’t begin until both the Secretary’s and the Treasurer’s offices are filled. However a number of factors have slowed the pace of filling Federal appointments, including the Treasurer’s Office. Until a new Treasurer is approved the existing 2017 series will keep being made.
More than you probably want to know:
The series-date rules are the reason you won’t find bills for each year on the calendar. Since the 1970s it’s been uncommon for a president to have more than one or two Treasury Secretaries in their cabinets, so the majority of bills have dates that match the start of each administration.
If the Treasurer’s office changes during an administration it doesn’t trigger a new series date. Instead, a suffix letter is added to the existing series date. For obscure reasons the series letters lag the number of Treasurers by one: Bills issued under the first Treasurer for a particular Secretary don’t have a series letter, if a second Treasurer takes office bills get an “A” after the date, a third would get a “B” and so on. A new series of bills can’t be started until that office is filled.
Until the early 1970s the triggers for changing a series date were different. In general, a new series date started only when a new design was issued. When either of the two Treasury officers changed only the series letter would change.
That practice came to an end because the design of the $1 bill had remained effectively ossified for nearly 3 decades. The absurd result was that Series 1935 bills were still being printed during the Johnson Administration.
Yet we have had new treasury secretaries since 2017