Using the Applicable Convention: Business Depreciation (2025 IRS Guide)

This guide covers “Using the Applicable Convention” within business depreciation. The following material presents the IRS treatment of this topic, including the qualifications, exceptions, and examples in the source section. Read the rules alongside the facts of your own situation before deciding what to report, deduct, or document.

Adapted from Publication 946 (2025), How To Depreciate Property, published by the Internal Revenue Service. This guide retains the source edition’s years, amounts, deadlines, and examples. It is guidance for that edition, not a statement that the same figures apply to every tax year.

Context for these rules

Instead of using the rates in the percentage tables to figure your depreciation deduction, you can figure it yourself. Before making the computation each year, you must reduce your adjusted basis in the property by the depreciation claimed the previous year(s).

Using the Applicable Convention

The applicable convention (discussed earlier under Which Convention Applies) affects how you figure your depreciation deduction for the year you place your property in service and for the year you dispose of it. It determines how much of the recovery period remains at the beginning of each year, so it also affects the depreciation rate for property you depreciate under the straight line method. See Straight line rate in the previous discussion. Use the applicable convention, as explained in the following discussions.

Half-year convention.

If this convention applies, you deduct a half-year of depreciation for the first year and the last year that you depreciate the property. You deduct a full year of depreciation for any other year during the recovery period.

Figure your depreciation deduction for the year you place the property in service by dividing the depreciation for a full year by 2. If you dispose of the property before the end of the recovery period, figure your depreciation deduction for the year of the disposition the same way. If you hold the property for the entire recovery period, your depreciation deduction for the year that includes the final 6 months of the recovery period is the amount of your unrecovered basis in the property.

Mid-quarter convention.

If this convention applies, the depreciation you can deduct for the first year you depreciate the property depends on the quarter in which you place the property in service.

A quarter of a full 12-month tax year is a period of 3 months. The first quarter in a year begins on the first day of the tax year. The second quarter begins on the first day of the fourth month of the tax year. The third quarter begins on the first day of the seventh month of the tax year. The fourth quarter begins on the first day of the tenth month of the tax year. A calendar year is divided into the following quarters.

Figure your depreciation deduction for the year you place the property in service by multiplying the depreciation for a full year by the percentage listed below for the quarter you place the property in service.

If you dispose of the property before the end of the recovery period, figure your depreciation deduction for the year of the disposition by multiplying a full year of depreciation by the percentage listed below for the quarter you dispose of the property.

If you hold the property for the entire recovery period, your depreciation deduction for the year that includes the final quarter of the recovery period is the amount of your unrecovered basis in the property.

Mid-month convention.

If this convention applies, the depreciation you can deduct for the first year that you depreciate the property depends on the month in which you place the property in service. Figure your depreciation deduction for the year you place the property in service by multiplying the depreciation for a full year by a fraction. The numerator of the fraction is the number of full months in the year that the property is in service plus ½ (or 0.5). The denominator is 12.

If you dispose of the property before the end of the recovery period, figure your depreciation deduction for the year of the disposition the same way. If you hold the property for the entire recovery period, your depreciation deduction for the year that includes the final month of the recovery period is the amount of your unrecovered basis in the property.

Example.

You use the calendar year and place nonresidential real property in service in August. The property is in service 4 full months (September, October, November, and December). Your numerator is 4.5 (4 full months plus 0.5). You multiply the depreciation for a full year by 4.5/12, or 0.375.

Using the guidance

Keep the documents that establish the dates, amounts, and circumstances described above. References to other chapters, forms, worksheets, or earlier and later sections refer to the linked IRS publication. Check the full publication and its updates before relying on a rule for a different tax year or a situation not addressed here.

Sources and further reading

• Publication 946 (2025), How To Depreciate Property: Figuring Depreciation Under MACRS — How Is the Depreciation Deduction Figured? — Figuring the Deduction Without Using the Tables — Using the Applicable Convention — Internal Revenue Service; 2025 edition.

The cited U.S. government text is in the public domain. Source accessed October 28, 2026. Fynoptic has organized this material for educational use and is independent of, and not endorsed by, the IRS.