(a) Allowance of deduction. Section 172(a) allows as a deduction in computing taxable income for any taxable year subject to the Code the aggregate of the net operating loss carryovers and net operating loss carrybacks to such taxable year. This deduction is referred to as the net operating loss deduction. The net operating loss is the basis for the computation of the net operating loss carryovers and net operating loss carrybacks and ultimately for the net operating loss deduction itself. The net operating loss deduction shall not be disallowed for any taxable year merely because the taxpayer has no income from a trade or business for the taxable year.

(b) Steps in computation of net operating loss deduction. The three steps to be taken in the ascertainment of the net operating loss deduction for any taxable year subject to the Code are as follows:

(1) Compute the net operating loss for any preceding or succeeding taxable year from which a net operating loss may be carried over or carried back to such taxable year.

(2) Compute the net operating loss carryovers to such taxable year from such preceding taxable years and the net operating loss carrybacks to such taxable year from such succeeding taxable years.

(3) Add such net operating loss carryovers and carrybacks in order to determine the net operating loss deduction for such taxable year.

(c) Statement with tax return. Every taxpayer claiming a net operating loss deduction for any taxable year shall file with his return for such year a concise statement setting forth the amount of the net operating loss deduction claimed and all material and pertinent facts relative thereto, including a detailed schedule showing the computation of the net operating loss deduction.

(d) Ascertainment of deduction dependent upon net operating loss carryback. If the taxpayer is entitled in computing his net operating loss deduction to a carryback which he is not able to ascertain at the time his return is due, he shall compute the net operating loss deduction on his return without regard to such net operating loss carryback. When the taxpayer ascertains the net operating loss carryback, he may within the applicable period of limitations file a claim for credit or refund of the overpayment, if any, resulting from the failure to compute the net operating loss deduction for the taxable year with the inclusion of such carryback; or he may file an application under the provisions of section 6411 for a tentative carryback adjustment.

(e) Law applicable to computations.

(1) In determining the amount of any net operating loss carryback or carryover to any taxable year, the necessary computations involving any other taxable year shall be made under the law applicable to such other taxable year.

(2) The net operating loss for any taxable year shall be determined under the law applicable to that year without regard to the year to which it is to be carried and in which, in effect, it is to be deducted as part of the net operating loss deduction.

(3) The amount of the net operating loss deduction which shall be allowed for any taxable year shall be determined under the law applicable to that year.

(f) Electing small business corporations. In determining the amount of the net operating loss deduction of any corporation, there shall be disregarded the net operating loss of such corporation for any taxable year for which such corporation was an electing small business corporation under subchapter S (section 1371 and following), chapter 1 of the Code. In applying section 172(b)(1) and (2) to a net operating loss sustained in a taxable year in which the corporation was not an electing small business corporation, a taxable year in which the corporation was an electing small business corporation is counted as a taxable year to which such net operating loss is carried back or over. However, the taxable income for such year as determined under section 172(b)(2) is treated as if it were zero for purposes of computing the balance of the loss available to the corporation as a carryback or carryover to other taxable years in which the corporation is not an electing small business corporation. See section 1374 and the regulations thereunder for allowance of a deduction to shareholders for a net operating loss sustained by an electing small business corporation.

(g) Husband and wife. The net operating loss deduction of a husband and wife shall be determined in accordance with this section, but subject also to the provisions of §1.172-7.

[T.D. 6500, 25 FR 11402, Nov. 26, 1960, as amended by T.D. 8107, 51 FR 43345, Dec. 2, 1986]