26 CFR §301.6501(m)-1 — (m)-1 Tentative carryback adjustment assessment period.

1. (a)Period of limitation after tentative carryback adjustment.
   1. (1)Under section 6501(m), in a case where an amount has been applied, credited, or refunded under section 6411, by reason of a net operating loss carryback, a capital loss carryback, an investment credit carryback, or a work incentive program credit carryback to a prior taxable year, the period described in section 6501(a) of the Code for assessing a deficiency for such prior taxable year is extended to include the period described in section 6501 (h), (j), or (o), whichever is applicable; except that the amount which may be assessed solely by reason of section 6501(m) may not exceed the amount so applied, credited, or refunded under section 6411, reduced by any amount which may be assessed solely by reason of section 6501 (h), (j), or (o), as the case may be.
   2. (2)The application of this paragraph may be illustrated by the following example:
2. (b)Effective date. The provisions of paragraph (a) of this section apply only with respect to applications under section 6411 filed after November 2, 1966.