Offer in Compromise
If you have IRS debt, you might know about an Offer In Compromise (OIC). This is the "settlement" that you hear about on TV and radio ads. As great as this resolution sounds, it is quite rare. Very few cases are settled using this method--only 0.1% of cases.
However, it certainly is possible in the right situation. The IRS commonly accepts OICs for older, disabled, or those with limited income or other circumstances.