There is talk that Jackson's likeness is being replaced by Harriet Tubman's likeness. If it happens I feel that this is the year for it: ( in the year of Juneteenth). It only seems reasonable to get a graded Jackson $20 bill before the likenesses are switched out. What do you think and where can I get a graded Jackson $20 bill before and if it is changed?
US currency isn't easily changed by the government like is done with the designs of state quarters. I would expect Jackson's portrait to remain on new $20 notes for another 5-8 years, at least. Even then the timeline could change or the plan could be indefinitely shelved depending who is President or Secretary of the Treasury by then. In terms of where to get a graded $20 note, you can see if your local or nearest coin shop has them available in their inventory. Aside from that, the easiest venue would be eBay.
A Jackson $20 will be worth face value forever, unless it's in mint condition and bears a fancy serial #.
I wouldn't hurry. The Biden Administration originally said it was going to speed up the process of replacing Jackson with Harriet Tubman on the $20, but it sounds like nothing, or very little, has happened on this topic yet. Some recent articles say the topic keeps getting "kicked down the road." The Bureau of Printing and Engraving cites time for designing a secure bill, but other groups have written to the White House to get an idea of a new timeline. Barring any new announcements, it still seems completely up in the air. Assuming that anything happens, I would also wait to get the printing numbers of the "final year" before paying to get something certified. Typically, the first and last issues of a series get hoarded and saved in bulk, reducing their value considerably, but that might vary greatly depending on the print run for each Federal Reserve Bank.
President Jackson has been on the $20 FRN for so long I doubt that you'd have any difficulty finding a nice example even a hundred years from now. For instance, I think my grandfather only paid about $40 for this particular note a few years ago. Regardless, if you're in the market for such an item, I'd recommend eBay or any of the numerous online third-party vendors. Edit: As of April 2021, the Federal Government is still printing Series of 2017-A $20 Federal Reserve Notes bearing President Jackson's portrait. https://www.moneyfactory.gov/images/7-Apr_FY21_End_of_the_Month_Report_5.4.2021.pdf
If you absolutely positively cannot wait until whenever if ever they come out with the bills, you can take matters into your own hands: https://www.walmart.com/ip/Harriet-...10367?wmlspartner=wlpa&selectedSellerId=11652