Form 8866 Interest Computation Under the Look-Back Method for Prop

Note: The draft you are looking for begins on the next page.

Caution: DRAFT—NOT FOR FILING

This is an early release draft of an IRS tax form, instructions, or publication,
which the IRS is providing for your information. Do not file draft forms. We
incorporate all significant changes to forms posted with this coversheet.
However, unexpected issues occasionally arise, or legislation is passed—in this
case, we will post a new draft of the form to alert users that changes were made
to the previously posted draft. Thus, there are never any changes to the last
posted draft of a form and the final revision of the form. Forms and instructions
are subject to OMB approval before they can be officially released, so we post
drafts of them until they are approved. Drafts of instructions and pubs usually
have some additional changes before their final release. Early release drafts are
at IRS.gov/DraftForms and remain there after the final release is posted at
IRS.gov/LatestForms. Also see IRS.gov/Forms.
Most forms and publications have a page on IRS.gov: IRS.gov/Form1040 for
Form 1040; IRS.gov/Pub501 for Pub. 501; IRS.gov/W4 for Form W-4; and
IRS.gov/ScheduleA for Schedule A (Form 1040), for example, and similarly for
other forms, pubs, and schedules for Form 1040. When typing in a link, type it
into the address bar of your browser, not a Search box on IRS.gov.
If you wish, you can submit comments to the IRS about draft or final forms,
instructions, or pubs at IRS.gov/FormsComments. Include “NTF” followed by the
form or pub number (for example, “NTF1040”, “NTFW4”, “NTF501”, etc.) in the
body of the message to route your message properly. We cannot respond to all
comments due to the high volume we receive and may not be able to consider
many suggestions until the subsequent revision of the product, but we will
review each “NTF” message. If you have comments on reducing paperwork and
respondent (filer) burden, with respect to draft or final forms, please respond to
the relevant information collection through the Federal Register process; for
more info, click here.

TREASURY/IRS AND OMB USE ONLY DRAFT

8866

Form
(Rev. December 2025)
Department of the Treasury
Internal Revenue Service

Interest Computation Under the Look-Back Method for
Property Depreciated Under the Income Forecast Method

OMB No. 1545-1622

Go to www.irs.gov/Form8866 for instructions and the latest information.

Attachment
Sequence No. 108

For the recomputation year beginning

, and ending

. See instructions.

Name

A

Identifying number

Number, street, and apt., room, or suite no. If a P.O. box, see instructions.

B

Check applicable box to show type of taxpayer:

City or town

State or province

ZIP or foreign postal code

Corporation

S corporation

Individual

Partnership

Estate or trust
C

If you were an owner of an interest in a pass-through entity (such as a partnership or an S corporation) that depreciated one or more properties to which this interest
computation relates, enter the name and employer identification number of the entity. Attach a schedule if there is more than one such entity.
Employer identification number

Name of entity:

Pass-through entities: Skip lines 1, 3, 4, and 5.
Taxable income (or loss) for the prior years shown on tax return (or
as previously adjusted) before net operating loss or capital loss
carrybacks (other than carrybacks that must be taken into account
to properly compute interest under section 167(g)) (see instructions).
If you were required to file Form 8866 for an earlier year, enter
adjusted taxable income for the prior years from Form 8866, line 3,
for the most recent recomputation year that affects the prior years.
Adjustment to taxable income for the difference between: (a) the
depreciation deducted under the income forecast method based
on estimated future income and (b) depreciation allowable under
the income forecast method based on actual income earned for
periods before the end of the recomputation year and estimated
future income to be earned after the recomputation year. See
instructions and attach a schedule listing each separate property,
unless you were an owner of an interest in a pass-through entity.

2

Prior Years

Recomputation
Year
Year ended
mo.

yr.

(a)

(b)

Year ended

Year ended

mo.

yr.

mo.

(c)
Totals
(Add columns (a) and (b))

yr.

3

Adjusted taxable income for look-back purposes. Combine
lines 1 and 2. If line 3 is a negative amount, see instructions

4

Income tax liability on line 3 amount using tax rates in
effect for the prior years (see instructions)
. . . .

5

Income tax liability shown on return (or as previously
adjusted) for the prior years (see instructions). If you were
required to file Form 8866 for an earlier year, enter the
amount required to be reported on Form 8866, line 4, for the
most recent recomputation year that affects the prior years

6

Increase (or decrease) in tax for the prior years on which
interest is due (or is to be refunded). Subtract line 5 from
line 4. (Pass-through entities: See instructions.)
. .

7

Interest due on increase, if any, shown on line 6 (see instructions)

8

Interest to be refunded on decrease, if any, shown on line
6 (see instructions)
. . . . . . . . . . .

9a

Net interest to be refunded to you. If line 8, column (c), is greater than line 7, column (c), enter the excess. File Form
8866 separately. Do not attach it to your tax return (see instructions) . . . . . . . . . . . . . . .

b

Routing number

d

Account number

10

c Type:

Checking

Savings

Net interest you owe. If line 7, column (c), is greater than line 8, column (c), enter the excess. Attach Form 8866 to
your tax return. See instructions for where to include this amount on your return . . . . . . . . . . .

Signatures. Complete this section only if this form is being filed separately and not with the tax return.
Under penalties of perjury, I declare that I have examined this form, including accompanying schedules and statements, and to the best of my knowledge
and belief, it is true, correct, and complete. Declaration of preparer (other than taxpayer) is based on all information of which preparer has any knowledge.

Sign
Here

Paid
Preparer
Use Only

Your signature

Date

Spouse’s signature. If a joint return, both spouses must sign.

Date

Preparer’s name

Preparer’s signature

Date

Check

if

PTIN

self-employed
Firm’s name

Firm’s EIN

Firm’s address

For Privacy Act and Paperwork Reduction Act Notice, see instructions.

Phone no.
Cat. No. 26036C

Form

8866 (Rev. 12-2025) Created 5/15/25

DRAFT — DO NOT FILE

DRAFT — DO NOT FILE

1