- 10 - the CDP Notice if the taxpayer did not receive a statutory notice of deficiency for such liability or did not otherwise have an opportunity to dispute such liability. Receipt of a statutory notice of deficiency for this purpose means receipt in time to petition the Tax Court for a redetermination of the deficiency asserted in the notice of deficiency. An opportunity to dispute a liability includes a prior opportunity for a conference with Appeals that was offered either before or after the assessment of the liability.[5] Where, as here, respondent has promulgated interpretive regulations with respect to a statutory provision, we have generally applied the analysis set forth by the Supreme Court in National Muffler Dealers Association, Inc. v. United States, 440 U.S. 472 (1979). Under National Muffler, an interpretive regulation is valid if it implements a congressional mandate in a reasonable manner. Id. at 476-477. An interpretive regulation 5The regulations have been amended, and the answer A-E2 now provides: A taxpayer is entitled to challenge the existence or amount of the underlying liability for any tax period specified on the CDP Notice if the taxpayer did not receive a statutory notice of deficiency for such liability or did not otherwise have an opportunity to dispute such liability. Receipt of a statutory notice of deficiency for this purpose means receipt in time to petition the Tax Court for a redetermination of the deficiency determined in the notice of deficiency. An opportunity to dispute the underlying liability includes a prior opportunity for a conference with Appeals that was offered either before or after the assessment of the liability. An opportunity for a conference with Appeals prior to the assessment of a tax subject to deficiency procedures is not a prior opportunity for this purpose. Sec. 301.6330-1(e)(3), Q&A-E2, Proced. & Admin. Regs. (applicable to requests for hearings on or after November 16, 2006).Page: Previous 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 NextLast modified: November 10, 2007