Millions of Americans rejoiced yesterday when the U.S. Treasury announced that it would replace Andrew Jackson with Harriet Tubman on the face of the $20 bill. However, their celebrations may be premature: It could be a decade or more before the bill is actually in circulation.

The problem is the slow pace at which the U.S. government typically moves to adopt change, according to Wired. In a letter posted on Medium, Treasury Secretary Jacob Lew said the Bureau of Engraving and Printing will unveil new looks for the $5, $10 and $20 bills in 2020 in honor of the 100th anniversary of women’s suffrage.

The new bills won’t go into circulation then, however; they’ll merely be shown to the public. It could take many more years to pass before the average American has a wallet full of Harriet Tubman $20s.

The hold-up is in part due to security concerns: The blue anti-counterfeit strip on the $100 bill took 15 years to develop. The Treasury is also committed to making the new bills more accessible for the visually impaired, meaning that they may have to develop new texture details. In true vague government fashion, a Treasury spokesperson said it’s impossible to predict when the new bills will be ready.

Tubman is not the only feminist who will appear on the redesigned bills. Revamped versions of the $10 bill will feature women’s rights activists Lucretia Mott, Sojourner Truth, Susan B. Anthony, Elizabeth Cady Stanton and Alice Paul, while new $5 bills will honor Marian Anderson and Eleanor Roosevelt. In all cases, it’s expected that these bills will be presented to the public in 2020, but it’s unclear when, exactly, they’ll be available to the public.

Read next: 9 Fascinating Facts About Harriet Tubman, the New Face of the $20 Bill

Some experts question whether we’ll ever be able to hold a Harriet bill in our hands. As startups like Square and currencies like Bitcoin gain popularity, some have gone so far as to predict the demise of cash—meaning that by the time Harriet is in circulation, carrying cash could be a thing of the past.

Still, that possibility seems unlikely: Cash in circulation in the U.S. grew 42% between 2007 and 2012, and its benefits—such as the inability to trace it—mean that some people will likely never stop using it, at least not within the next several decades.