26 C.F.R. § 1.534-3
In the case of a jeopardy assessment, a notice of deficiency is required to be sent to the taxpayer by registered mail (or by certified or registered mail, if the notice is mailed after September 2, 1958) within 60 days after the making of the assessment. See section 6861. If a jeopardy assessment is made before the mailing of the deficiency notice, then in the case of a proceeding in the Tax Court, if the deficiency notice informs the taxpayer that an amount of accumulated earnings tax is included in the deficiency, such notice shall constitute the notification provided for in section 534(b) and paragraph (c) of § 1.534-2 . Under such circumstances the statement described in section 534(c) and paragraph (d) of § 1.534-2 shall instead be included in the taxpayer's petition to the Tax Court, if the taxpayer desires to submit such statement. See paragraph (b) of § 1.534-2 , relating to burden of proof on the taxpayer.
26 C.F.R. §1.534-3