US Code

Public Law 119-73 (01/23/2026)

26 U.S.C. § 166

Bad debts

(a)

General rule

(1)

Wholly worthless debts

There shall be allowed as a deduction any debt which becomes worthless within the taxable year.

(2)

Partially worthless debts

When satisfied that a debt is recoverable only in part, the Secretary may allow such debt, in an amount not in excess of the part charged off within the taxable year, as a deduction.

(b)

Amount of deduction

For purposes of subsection (a), the basis for determining the amount of the deduction for any bad debt shall be the adjusted basis provided in section 1011 for determining the loss from the sale or other disposition of property.

[(c)

Pub. L. 99–514, title VIII, § 805(a)100 Stat. 2361 Repealed. , , ]

(d)

Nonbusiness debts

(1)

General rule

In the case of a taxpayer other than a corporation—
(A)
subsection (a) shall not apply to any nonbusiness debt; and
(B)
where any nonbusiness debt becomes worthless within the taxable year, the loss resulting therefrom shall be considered a loss from the sale or exchange, during the taxable year, of a capital asset held for not more than 1 year.
(2)

Nonbusiness debt defined

For purposes of paragraph (1), the term “nonbusiness debt” means a debt other than—
(A)
a debt created or acquired (as the case may be) in connection with a trade or business of the taxpayer; or
(B)
a debt the loss from the worthlessness of which is incurred in the taxpayer’s trade or business.
(e)

Worthless securities

This section shall not apply to a debt which is evidenced by a security as defined in section 165(g)(2)(C).

(f)

Cross references

(1)
For disallowance of deduction for worthlessness of debts owed by political parties and similar organizations, see section 271.
(2)
For special rule for banks with respect to worthless securities, see section 582.

Aug. 16, 1954, ch. 73668A Stat. 50Pub. L. 85–866, title I, § 872 Stat. 1608Pub. L. 89–722, § 1(a)80 Stat. 1151Pub. L. 91–172, title IV, § 431(c)(1)83 Stat. 619Pub. L. 94–455, title VI, § 605(a)90 Stat. 1575Pub. L. 98–369, div. A, title X, § 1001(b)(1)98 Stat. 1011Pub. L. 99–514, title VIII, § 805(a)100 Stat. 2361Pub. L. 100–647, title I, § 1008(d)(1)102 Stat. 3439(, ; , , ; , , ; , , ; , title XIV, § 1402(b)(1)(A), (2), title XIX, § 1906(b)(13)(A), , , 1731, 1732, 1834; , (e), , , 1012; , (b), title IX, § 901(d)(4)(A), , , 2379; , (2), , .)

Editorial Notes

Amendments

Pub. L. 100–647, § 1008(d)(1)1988—Subsec. (d)(1)(A). , substituted “subsection (a)” for “subsections (a) and (c)”.

Pub. L. 100–647, § 1008(d)(2)Pub. L. 99–514, § 805(b)Subsecs. (f), (g). , made clarifying amendment to directory language of , see 1986 Amendment note below.

Pub. L. 99–514, § 805(a)1986—Subsec. (c). , struck out subsec. (c), reserve for bad debts, which read as follows: “In lieu of any deduction under subsection (a), there shall be allowed (in the discretion of the Secretary) a deduction for a reasonable addition to a reserve for bad debts.”

Pub. L. 99–514, § 805(b)Pub. L. 100–647, § 1008(d)(2)Subsec. (f). , as amended by , redesignated subsec. (g) as (f) and struck out former subsec. (f) which related to reserve for certain guaranteed debt obligations, par. (1) thereof providing for allowance of deduction, par. (2) disallowing deduction in other cases, par. (3) relating to opening balance of reserve, and par. (4) relating to suspense account.

Pub. L. 99–514, § 805(b)Pub. L. 100–647, § 1008(d)(2)Subsec. (g). , as amended by , redesignated subsec. (g) as (f).

Pub. L. 99–514, § 901(d)(4)(A), struck out pars. (3) and (4) which read as follows:

“(3) For special rule for bad debt reserves of certain mutual savings banks, domestic building and loan associations, and cooperative banks, see section 593.

“(4) For special rule for bad debt reserves of banks, small business investment-companies, etc., see sections 585 and 586.”

Pub. L. 98–3691984—Subsec. (d)(1)(B). substituted “6 months” for “1 year”, applicable to property acquired after , and before . See Effective Date of 1984 Amendment note below.

Pub. L. 94–455, § 1906(b)(13)(A)1976—Subsecs. (a)(2), (c). , struck out “or his delegate” after “Secretary”.

Pub. L. 94–455, § 1401(b)(1)(A)Subsec. (d)(1)(B). , (2), provided that “6 months” would be changed to “9 months” for taxable years beginning in 1977, and “9 months” would be changed to “1 year” for taxable years beginning after .

Pub. L. 94–455Subsec. (f). , §§ 605(a), 1906(b)(13)(A), redesignated subsec. (g) as (f) and struck out “or his delegate” after “Secretary” in pars. (1), (3) and (4)(D). Former subsec. (f), which related to treatment of payments made by guarantors of certain noncorporate obligations, was struck out.

Pub. L. 94–455, § 605(a)Subsecs. (g), (h). , redesignated subsecs. (g) and (h) as (f) and (g), respectively.

Pub. L. 91–1721969—Subsec. (h)(4). added par. (4).

Pub. L. 89–7221966—Subsecs. (g), (h). added subsec. (g) and redesignated former subsec. (g) as (h).

Pub. L. 85–8661958—Subsec. (d)(2)(A). substituted “a trade or business of the taxpayer” for “a taxpayer’s trade or business”.

Statutory Notes and Related Subsidiaries

Effective Date of 1988 Amendment

Pub. L. 100–647Pub. L. 99–514section 1019(a) of Pub. L. 100–647section 1 of this titleAmendment by effective, except as otherwise provided, as if included in the provision of the Tax Reform Act of 1986, , to which such amendment relates, see , set out as a note under .

Effective Date of 1986 Amendment

Pub. L. 99–514, title VIII, § 805(d)100 Stat. 2362

“(1)

In general .—

The amendments made by this section [amending this section and sections 81, 108, 461, and 805 of this title] shall apply to taxable years beginning after .
“(2)

Change in method of accounting .—

In the case of any taxpayer who maintained a reserve for bad debts for such taxpayer’s last taxable year beginning before , and who is required by the amendments made by this section to change its method of accounting for any taxable year—
“(A)
such change shall be treated as initiated by the taxpayer,
“(B)
such change shall be treated as made with the consent of the Secretary, and
“(C)
the net amount of adjustments required by section 481 of the Internal Revenue Code of 1986 to be taken into account by the taxpayer shall—
“(i)
in the case of a taxpayer maintaining a reserve under section 166(f), be reduced by the balance in the suspense account under section 166(f)(4) of such Code as of the close of such last taxable year, and
“(ii)
be taken into account ratably in each of the first 4 taxable years beginning after .”
, , , provided that:

Pub. L. 99–514, title IX, § 901(e)100 Stat. 2380

section 586 of this title“The amendments made by this section [amending this section and sections 172, 291, 582, 585, 593, 596, 856, 1277, and 1361 of this title and repealing ] shall apply to taxable years beginning after .”
, , , provided that:

Effective Date of 1984 Amendment

Pub. L. 98–369, div. A, title X, § 1001(e)98 Stat. 1012

“The amendments made by this section [amending this section and sections 341, 402, 403, 423, 582, 584, 631, 642, 702, 818, 852, 856, 857, 1222, 1223, 1231, 1232, 1233, 1234, 1235, 1246, 1247, 1248, 1251, and 1278 of this title] shall apply to property acquired after , and before .”
, , , provided that:

Effective Date of 1976 Amendment

Pub. L. 94–455, title VI, § 605(c)90 Stat. 1575

section 81 of this title“The amendments made by this section [amending this section and ] shall apply to guarantees made after , in taxable years beginning after such date.”
, , , provided that:

Pub. L. 94–455, title XIV, § 1402(b)(1)90 Stat. 1731, , , provided that the amendment made by that section is effective with respect to taxable years beginning in 1977.

Pub. L. 94–455, title XIV, § 1402(b)(2)90 Stat. 1732, , , provided that the amendment made by that section is effective with respect to taxable years beginning after .

Effective Date of 1969 Amendment

Pub. L. 91–172section 431(d) of Pub. L. 91–172section 585 of this titleAmendment by applicable to taxable years beginning after , see , set out as an Effective Date note under .

Effective Date of 1966 Amendment

Pub. L. 89–722, § 280 Stat. 1152Pub. L. 99–514, § 2100 Stat. 2095

“(a)
section 81 of this title Except as provided in subsections (b) and (c), the amendments made by the first section of this Act [amending this section and ] shall apply to taxable years ending after .
“(b)
If—
“(1)
the taxpayer before , claimed a deduction, for a taxable year ending before such date, under section 166(c) of the Internal Revenue Code of 1986 [formerly I.R.C. 1954] for an addition to a reserve for bad debts on account of debt obligations described in section 166(g)(1)(A) of such Code (as amended by the first section of this Act), and
“(2)
the assessment of a deficiency of the tax imposed by chapter 1 of such Code for such taxable year and each subsequent taxable year ending before , is not prevented on , by the operation of any law or rule of law,
then such deduction on account of such debt obligations shall be allowed for each such taxable year under such section 166(c) to the extent that the deduction would have been allowable under the provisions of such section 166(g)(1)(A) if such provisions applied to such taxable years.
“(c)
Section 166(g)(2) of the Internal Revenue Code of 1986 (as amended by the first section of this Act) shall apply to taxable years beginning after , and ending after .”
, , , as amended by , , , provided that:

Effective Date of 1958 Amendment

Pub. L. 85–866section 1(c)(1) of Pub. L. 85–866section 165 of this titleAmendment by applicable to taxable years beginning after , and ending after , see , set out as a note under .

Establishment of Reserve for Taxable Year Ending After , and Beginning Before

Pub. L. 89–722, § 1(c)80 Stat. 1152Pub. L. 99–514, § 2100 Stat. 2095

“If the taxpayer establishes a reserve described in section 166(g)(1) of the Internal Revenue Code of 1986 [formerly I.R.C. 1954] (as amended by subsection (a) of this section) for a taxable year ending after , and beginning before , the establishment of such reserve shall not be considered as a change in method of accounting for purposes of section 446(e) of such Code.”
, , , as amended by , , , provided that: