Final determination

(a) A final determination for purposes of this Part includes but is not limited to the following:

(1) a closing agreement made under section 7121 of the Internal Revenue Code finally and irrevocably adjusting and settling a taxpayer's federal income tax liability;

(2) an allowance by the Commissioner of Internal Revenue of a refund of any part of the federal income tax shown on the taxpayer's federal income tax return or of any deficiency thereafter assessed, whether such refund is made on such Commissioner's own motion or pursuant to a judgment of a court;

(3) the 90-day deficiency notice pursuant to section 6212 of the Internal Revenue Code, unless a timely petition to redetermine the deficiency is filed in the Tax Court of the United States, in which event the judgment of the court of last resort affirming the deficiency, or the redetermination of the deficiency pursuant to a judgment of the court of last resort, is the final determination;

(4) the assessment of a deficiency pursuant to a waiver filed under section 6213 of the Internal Revenue Code where no 90-day deficiency notice is issued; and

(5) the allowance of a tentative carryback adjustment based on the net operating loss carryback pursuant to section 6411 of the Internal Revenue Code.