Usually good news: the IRS granted penalty relief
Letter 168C, also written as Letter 168-C, notifies you that a penalty has been removed or reduced. The IRS lists it as a reasonable-cause relief letter and also uses it to notify taxpayers of first-time abatement. Read your copy to see the reason for relief and exactly which penalties and tax periods it covers.
Check what changed and what you still owe
Compare the reduction with your original penalty notice and relief request. Removing a penalty does not by itself cancel the underlying tax or every other charge on the account. Review any remaining balance and payment instructions rather than assuming the entire matter is closed.
The IRS automatically reduces or removes interest related to a penalty that it reduces or removes. That is different from wiping out all interest on unpaid tax.
If the letter mentions first-time abatement
IRS procedures allow Letter 168C to explain that relief was based on your prior compliance history rather than a reasonable-cause explanation. They also warn that a failure-to-pay penalty can continue on unpaid tax. After paying the tax in full, ask the IRS whether any additional failure-to-pay penalty qualifies for removal.
What to do next
Keep the letter, original notice, relief request, and payment records together. Check the taxpayer name, tax period, penalty amount, and remaining balance. If the adjustment matches your records and the letter asks for no response, retain it for your files. Follow any specific payment or response date printed on the document; there is no universal response deadline supplied by this guide.
If the result does not match what you requested, contact the IRS using the verified contact information on the letter or have your tax professional review it. A partial reduction may leave issues unresolved, so do not discard related correspondence.