If the Secretary believes that the assessment or collection of a deficiency, as defined in section 6211, will be jeopardized by delay, he shall, notwithstanding the provisions of section 6213(a), immediately assess such deficiency (together with all interest, additional amounts, and additions to the tax provided for by law), and notice and demand shall be made by the Secretary for the payment thereof.
If the jeopardy assessment is made before any notice in respect of the tax to which the jeopardy assessment relates has been mailed under section 6212(a), then the Secretary shall mail a notice under such subsection within 60 days after the making of the assessment.
The jeopardy assessment may be made in respect of a deficiency greater or less than that notice of which has been mailed to the taxpayer, despite the provisions of section 6212(c) prohibiting the determination of additional deficiencies, and whether or not the taxpayer has theretofore filed a petition with the Tax Court. The Secretary may, at any time before the decision of the Tax Court is rendered, abate such assessment, or any unpaid portion thereof, to the extent that he believes the assessment to be excessive in amount. The Secretary shall notify the Tax Court of the amount of such assessment, or abatement, if the petition is filed with the Tax Court before the making of the assessment or is subsequently filed, and the Tax Court shall have jurisdiction to redetermine the entire amount of the deficiency and of all amounts assessed at the same time in connection therewith.
If the jeopardy assessment is made after the decision of the Tax Court is rendered, such assessment may be made only in respect of the deficiency determined by the Tax Court in its decision.
A jeopardy assessment may not be made after the decision of the Tax Court has become final or after the taxpayer has filed a petition for review of the decision of the Tax Court.
When the petition has been filed with the Tax Court and when the amount which should have been assessed has been determined by a decision of the Tax Court which has become final, then any unpaid portion, the collection of which has been stayed by bond as provided in section 6863(b) shall be collected as part of the tax upon notice and demand from the Secretary, and any remaining portion of the assessment shall be abated. If the amount already collected exceeds the amount determined as the amount which should have been assessed, such excess shall be credited or refunded to the taxpayer as provided in section 6402, without the filing of claim therefor. If the amount determined as the amount which should have been assessed is greater than the amount actually assessed, then the difference shall be assessed and shall be collected as part of the tax upon notice and demand from the Secretary.
The Secretary may abate the jeopardy assessment if he finds that jeopardy does not exist. Such abatement may not be made after a decision of the Tax Court in respect of the deficiency has been rendered or, if no petition is filed with the Tax Court, after the expiration of the period for filing such petition. The period of limitation on the making of assessments and levy or a proceeding in court for collection, in respect of any deficiency, shall be determined as if the jeopardy assessment so abated had not been made, except that the running of such period shall in any event be suspended for the period from the date of such jeopardy assessment until the expiration of the 10th day after the day on which such jeopardy assessment is abated.