What is the mid-month convention for residential rental depreciation?

Under IRC §168(d)(2), residential rental property (27.5-year) and non-residential real property (39-year) use the mid-month convention. This means the property is treated as placed in service on the 15th of the month it was actually placed in service, regardless of the actual date. You receive half a month of depreciation in both the month of placement and the month of disposition.

What is the half-year convention for STR personal property?

The half-year convention applies to 5-year and 7-year MACRS personal property (furniture, appliances, equipment). Regardless of when during the year you place the asset in service, you receive exactly one-half year of depreciation in Year 1. This means an asset placed in service on January 1 and one placed in service on December 30 both receive the same Year 1 depreciation under the half-year convention.

What is the mid-quarter convention and when does it apply?

The mid-quarter convention applies to personal property (5-year, 7-year MACRS) when more than 40% of the depreciable personal property placed in service during the year is placed in service in the fourth quarter (October–December). Under mid-quarter, each asset is treated as placed in service on the 15th of the quarter's middle month, which significantly reduces first-year depreciation for Q4 assets.

Does bonus depreciation eliminate concern about these conventions?

For assets that qualify for 100% bonus depreciation (5-year and 15-year MACRS property), the half-year and mid-quarter conventions are irrelevant because you're deducting 100% of the cost in Year 1 regardless. The conventions matter most for assets using standard MACRS depreciation — primarily the building structure, which cannot receive bonus depreciation.

April 6, 2026 · 7 min read

Mid-Month Convention: When to Place Assets in Service for Depreciation

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Under IRC §168(d)(2), residential rental property (27.5-year) uses the mid-month convention—treating the asset as placed in service on the 15th of the month regardless of actual date. Personal property like furniture uses the half-year convention, giving you a half-year of depreciation in Year 1 regardless of when you purchased it. Understanding these rules prevents miscalculating your first-year deductions.

The Three MACRS Depreciation Conventions

The IRS uses three different timing conventions to determine how much depreciation you can claim in the year an asset is placed in service. The convention that applies depends on the type of property:

Convention	Applies To	Year 1 Treatment
Mid-Month	27.5-year and 39-year real property	15th of the month placed in service
Half-Year	5-year, 7-year personal property (default)	One-half year regardless of date
Mid-Quarter	5/7-year property if >40% placed in Q4	15th of middle month of each quarter

Mid-Month Convention: How It Works for Your Building

The mid-month convention governs depreciation on your STR building structure. Under this convention, any residential rental property placed in service during a month is treated as placed in service on the 15th of that month. This applies uniformly—whether you closed on January 2 or January 30, you get the same Year 1 depreciation for January placement.

Mid-Month Convention Examples: $400,000 Building

27.5-Year Residential Rental

Annual depreciation: $400,000 ÷ 27.5 = $14,545.45/year. Monthly rate: $14,545.45 ÷ 12 = $1,212.12/month.

January placement (11.5 months of credit): $1,212.12 × 11.5 = $13,939 Year 1
July placement (5.5 months of credit): $1,212.12 × 5.5 = $6,667 Year 1
October placement (2.5 months of credit): $1,212.12 × 2.5 = $3,030 Year 1
December placement (0.5 months of credit): $1,212.12 × 0.5 = $606 Year 1

This math shows why timing matters for the building. Placing an STR in service in January versus December generates a nearly $13,000 difference in first-year building depreciation on a $400,000 building basis.

Half-Year Convention: Personal Property Rules

The half-year convention applies to 5-year and 7-year MACRS personal property (furniture, appliances, electronics). Under this convention, every asset placed in service during the year is treated as if it was placed in service exactly halfway through the year—regardless of whether you bought it in January or December.

For a $10,000 piece of furniture classified as 5-year property using 200% declining balance MACRS:

Year 1: 20% × $10,000 × (1/2 year) = $1,000 (half-year applied)
Year 2: 32% × $10,000 = $3,200
Year 3: 19.2% × $10,000 = $1,920

Bonus Depreciation Eliminates the Timing Issue

For any 5-year or 15-year property that qualifies for 100% bonus depreciation, the half-year convention is irrelevant—you deduct 100% in Year 1 regardless of when you bought it. The conventions matter most for assets on standard MACRS (primarily your building structure) or if you elect out of bonus depreciation.

The Mid-Quarter Convention: The Q4 Trap

The mid-quarter convention is triggered when more than 40% of your depreciable personal property is placed in service in the fourth quarter (October 1 through December 31). This is sometimes called the "Q4 trap" because it significantly reduces Year 1 depreciation for Q4 assets.

The Q4 Trap

If you buy $5,000 of new equipment in February and $20,000 of furniture in November (total $25,000), 80% of your personal property purchases are in Q4. The mid-quarter convention applies to all personal property. Q4 assets get only 1.5 months of depreciation in Year 1 (treated as placed in service November 15). Q1 assets get 10.5 months. This is a significant reduction from the half-year convention. Spreading large purchases across quarters can avoid the trigger.

When Timing Really Matters: A Year-End Planning Guide

Asset Type	Convention	Does Timing Within Year Matter?
STR building (27.5-yr)	Mid-Month	Yes — each month = 1/12 of annual depreciation
Furniture/appliances (5-yr standard MACRS)	Half-Year*	Minimal — always 1/2 year in Year 1
Furniture/appliances (5-yr bonus dep)	N/A	No — 100% deducted in Year 1
Land improvements (15-yr standard MACRS)	Half-Year*	Minimal — always 1/2 year in Year 1
Land improvements (15-yr bonus dep)	N/A	No — 100% deducted in Year 1

*Mid-quarter convention applies if >40% of personal property placed in Q4.

Placed in Service: What It Means

An asset is "placed in service" when it is ready and available for use in your rental activity—not when you order it, not when you pay for it, but when it is operational and available. For an STR building, this is typically the date it is listed and available for guests. For furniture, it is the date it is installed in the unit and available for use.

Year-End Strategy

If you're buying equipment or furniture in December and want to count it in the current tax year, make sure it is physically delivered, set up, and available for use before December 31. An order placed December 28 that doesn't arrive until January 5 is a next-year asset. Keep receipts, photos, and delivery records showing the date the asset was ready for use.

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Disclaimer

This article is for informational purposes and does not constitute tax, legal, or financial advice. Tax rules vary based on your specific situation, filing status, entity structure, and jurisdiction. Always consult a qualified CPA or tax professional for guidance on your specific tax situation. IRS rules and thresholds are subject to change—verify current requirements at irs.gov before filing.