How long do you have to worry about unfiled tax returns

At least 6 years. Usually it is 6 years from the date that you were suppose to file and didn't.

Not until you have actually filed a return can the 3/10 year limits come into play. 3 year limit on audit and 10 year limit on collection (serious stipulations on 10 year collection limit - visit irs.gov for exact tax code)

With all thing being considered, it would be better to file a past due return as soon as possible.

If you had a death in the immediate family, or you or your spouse were under the care of a doctor - you may qualify for an abatement of penalties (meaning you might not have to pay all of the penalties) You can contact us or your tax professional for more information.

For tax code and tax law, visit irs.gov