All United States citizens and residents are required to file tax returns if they meet certain income threshhold levels. Although these have changed over the years, and although the income levels vary slightly depending on the age of the citizen or resident, each year's requirement can be found on IRS' website (www.irs.gov), or in Section 6012 of the Tax Code. Failure to file can be a criminal or non-criminal violation, and can subject the taxpayer to penalties and interest.
In cases where no refund was filed, Section 6511 of the Tax Code states that a claim for refund must be filed within two years from the time that the tax was paid ir withheld; these deadlines may be extended in cases where the taxpayer was "disabled"-- as that term is defined in the Tax Code and as it has been interpreted by the Courts.
In cases where a return was not filed, the law provides most taxpayers with a three-year window of opportunity for claiming a refund. If no return is filed to claim the refund within the three years, the money becomes the property of the U.S. Treasury. After the expiration of the refund statute, not only does the law prevent the issuance of a refund check, it also prevents the application of any credits, including overpayments of estimated or withholding taxes, to other tax years that are underpaid.
On the other hand, the statute of limitations for IRS to assess and collect any outstanding balances does not start until a return has been filed. In other words, there is no statute of limittions for assessing and collecting the tax if no return has been filed.
You should get a recommendation of a CPA who specializes in representing taxpayers who have failed to file returns. You have an obligation to file a return for each year in which you have taxable income. It is better to be safe than sorry. Get competent advice. Don't hide. Sleep well at night. In a one or two hour consultation you will know your alternatives.
Oh the choices you have.
1) Ignore the problem. Let the statute of limitations run out. if you hear from them then you will have more choices thrust upon you.
2) Create the tax returns. See if you owed the IRS money (including potential late filing fees, etc). If you don't they do not really care whether you file the returns. If you do then decide which year's returns you want to file.
3) File the returns whether you owe the IRS money or not. If you owe then late fees, penalties will apply. The IRS is more lenient on taxpayers who self-disclose their wrong-doings than the ones they find out about and confront.
4) Move to a country without an extradition treaty with the U.S.