Note:

By signing Form 4089 or Form 870-EP, the taxpayer waives his/her right to petition tax court. As a result, the additional time by which the statute of limitations was "extended" (by issuance of the 90-day letter) is shortened by the amount of time remaining from the date the taxpayer signed Form 4089 or Form 870-EP to the deadline to petition tax court.

Monitor the case during the 90-Day suspense period to determine if the taxpayer petitioned the U.S. Tax Court by researching dawson.ustaxcourt.gov/, and completing a "Docket Inquiry" (use Microsoft Edge).

The issuance of a SNOD begins the litigation process. Once you issue the 90-Day Letter, make note to take action on the case on the earlier of:

105 days (90 days plus 15 days).

The date the taxpayer petitions tax court.

The date the taxpayer files the appropriate waiver.

If the taxpayer agrees to the deficiency by signing Form 4089 or Form 870-EP, close the case following agreed case closing procedures.