Get this taken care of as SOON AS POSSIBLE. The problem will NOT go away, they will come after you, freeze your assets, garnish your wages, and the fines and penalties will be so severe that you will wonder how the heck your back taxes and penalties add up to more than you make in a year, or in several years.
A high school friend had this problem a few years back, as he moved around a lot for a period of years then settled down. Didn't file taxes as he lived pretty much hand to mouth for a while, and pretty much worked for cash as best he could. He figured he was such small potatoes, the IRS would never waste their time.
As was said above, there is NO statute of limitations if you owe taxes, and they WILL get whatever they think they are owed and then some. They can't take away the tools of your trade, and some other stuff, but in my friends case, the amount of money he owed with penalties ended up being more than everything he owned put together, several times over. Just crazy..
Anyway, good luck. The $20 thing sounds like it's too good to be true. Tax attorney guys around here charge $200 an hour plus, and they have lots of business. Deal with the IRS directly, explain your situation, and see what you can work out. If you ignore it, things may stay quiet for a few months, and you may think they forgot about you... They WILL come back, and the penalties just keep adding up.
My friend is now basically working to pay off the crap he owes to the IRS for god knows how long, unless he gets a much better job, and its for stuff he did like 15 years ago, for what seemed like chump change at the time.
Get this taken care of now.
Billy
Montgomery Village, MD