Security System Depreciation Life: Recovery Periods and Section 179

A business security system doesn’t have one depreciation life. The security system depreciation life depends on how each component is classified: standalone equipment like cameras, recorders, and monitors generally sits in the 5-year class, control units and keypads often land at 7 years, interior improvements and outdoor infrastructure recover over 15 years, systems in residential rental buildings run 27.5 years, and anything treated as a structural part of a nonresidential building defaults to 39 years. In practice, most businesses never ride those schedules out. Section 179 and the 100% bonus depreciation restored by the One, Big, Beautiful Bill Act in 2025 let you deduct the full cost of a qualifying system in the year it goes into service.

Recovery Periods by Component

The IRS analyzes a security system separately from the building it sits in, which is what makes the split across multiple recovery periods possible.¹ The dividing line is whether a given component is tangible personal property (removable without damaging the building) or a structural component (conduit in walls, hardwired panels tied into the building’s electrical system, cabling run through ceilings). Classification drives everything that follows.

5-Year Property

Electronic equipment with a distinct, identifiable function sits in the 5-year class under the Modified Accelerated Cost Recovery System. IRS Publication 946 lists computers and peripheral equipment here, and security cameras, NVRs, DVRs, and dedicated monitoring servers fall in as qualified technological equipment.² For most installations, this is where the bulk of the dollar value sits.

7-Year Property

The 7-year class is the MACRS catch-all for tangible personal property that doesn’t fit cleanly elsewhere. Intercom handsets, alarm keypads, motion detectors, and control units that are more than simple computer peripherals but still removable commonly land here. The line between 5-year and 7-year property can be blurry, and a cost segregation study is the most reliable way to sort components.

15-Year Property

Two kinds of security-related costs recover over 15 years. Interior improvements to a nonresidential building that don’t enlarge it, add an elevator, or alter its structural framework can qualify as Qualified Improvement Property.³ Running new conduit through existing walls, cutting access points for card readers, or mounting brackets that become part of the interior finish can fit. Outdoor security infrastructure classified as a land improvement also lands in the 15-year class: perimeter fencing, camera poles cemented into the ground, concrete pads for guard booths.²

27.5-Year Property (Residential Rental)

Security systems installed in residential rental buildings follow the building. The IRS treats improvements to residential rental property as having the same recovery period as the structure itself: 27.5 years under the General Depreciation System, using the mid-month convention.⁴ The Section 179 real property election doesn’t apply here, since it’s limited to nonresidential buildings. Landlords who want faster recovery should look at cost segregation to pull out components that qualify as tangible personal property with a 5-year or 7-year life.

39-Year Property

Any component classified as a structural element of a nonresidential building and not separated through cost segregation defaults to 39-year nonresidential real property. This is the outcome worth working to avoid. Once a project gets lumped into a single 39-year line item, unwinding it later requires an accounting method change with the IRS.

Section 179 Expensing

Section 179 lets a business deduct the full cost of qualifying property in the year it’s placed in service, skipping the multi-year schedule entirely. Security systems are explicitly eligible, both as tangible personal property and as qualifying improvements to nonresidential real property.⁵ The IRS groups them with roofs, HVAC equipment, and fire protection systems as improvements that qualify for the election even when treated as real property.

The One, Big, Beautiful Bill Act expanded the limits starting in 2025. For tax years beginning in 2026, the maximum deduction is $2,560,000, and the phase-out doesn’t begin until total qualifying property placed in service exceeds $4,090,000. Those thresholds are now permanent and adjust for inflation annually. The prior ceiling of roughly $1.2 million more than doubled.

A few constraints still apply. The property must be used more than 50% for business purposes. The deduction cannot exceed the taxpayer’s net taxable income from active trades or businesses for the year, and any excess carries forward rather than being lost. The election is made on IRS Form 4562, filed with the return for the year the system goes into service.⁶

Bonus Depreciation

Bonus depreciation, formally the additional first year depreciation deduction, allows an immediate write-off of qualifying property with a MACRS recovery period of 20 years or less.² That covers 5-year, 7-year, and 15-year security system components alike. Unlike Section 179, it has no dollar cap and no taxable-income limitation, so it can create or increase a net operating loss.

The percentage had been phasing down: 80% in 2023, 60% in 2024, and 40% for property placed in service in 2025 before the law changed. The One, Big, Beautiful Bill Act, signed in 2025, restored the deduction to a permanent 100% for qualified property acquired after January 19, 2025.⁷ For a system placed in service in 2026, every component with a recovery period of 20 years or less is fully deductible in year one.

Bonus depreciation applies automatically unless the taxpayer elects out for an entire property class on a timely filed return. A business expecting significantly higher income in a future year might choose to preserve the deductions. A taxpayer can also elect 40% bonus depreciation instead of 100% for qualified property placed in service during the first tax year ending after January 19, 2025.

Businesses commonly stack both provisions. Section 179 applies first, up to the taxable-income limit, and bonus depreciation covers whatever remains without regard to income.

Leased Systems Are Treated Differently

If the arrangement is a true lease, monthly payments are deductible as rent and nothing is depreciated. The business never owns the equipment and never claims Section 179 or bonus depreciation.⁸ Many “lease” agreements are conditional sales contracts in disguise, though. If the agreement transfers title after a set number of payments, includes a bargain purchase option, or charges well above fair rental value, the IRS treats it as a purchase. Getting the characterization wrong means either overstating deductions or missing out on first-year expensing.

When ADS Forces a Longer Schedule

Certain situations require the Alternative Depreciation System instead of GDS. ADS uses longer recovery periods and straight-line depreciation. A business must use ADS for security equipment used predominantly outside the United States, financed with tax-exempt bonds, leased to a tax-exempt entity, or classified as listed property used 50% or less for business. Businesses that elect out of the Section 163(j) interest deduction limitation must also use ADS for real property, including any security system components classified as nonresidential real property or QIP.²

Recapture When You Sell or Replace the System

Every dollar of depreciation claimed on security equipment creates a potential tax bill later. When you sell, trade in, or dispose of depreciated components, Section 1245 requires you to recapture the depreciation by treating part of the gain as ordinary income rather than capital gain.⁹

The recapture amount is the lesser of two numbers: the total depreciation claimed (including any Section 179 or bonus depreciation) or the gain realized on the disposition. If you took a full Section 179 deduction on a $50,000 camera system and later sold the equipment for $8,000, the entire $8,000 gain is ordinary income because the depreciation claimed exceeds the gain. Any gain above the recaptured depreciation is treated as a Section 1231 gain, which may qualify for long-term capital gains rates. Recapture is reported on Part III of Form 4797.⁹

This is the downside of aggressive first-year expensing. A system you fully expensed has an adjusted basis of zero, so any sale proceeds trigger ordinary income recapture. The time value of the upfront deduction usually still outweighs the future tax hit, but it catches business owners off guard when they upgrade and sell off the old equipment.

State Conformity Can Change the Picture

Federal depreciation rules don’t automatically flow through to state tax returns. States range from full conformity with federal bonus depreciation and Section 179 to complete decoupling, where the state ignores the accelerated deduction and requires its own schedule. Some conform with a delay or cap the bonus amount allowed. The practical effect: claiming 100% bonus depreciation federally may still leave you depreciating the security system over multiple years for state income tax. Check your state’s current conformity status before filing.

1
Internal Revenue Service. Tangible Property Final Regulations
2
Internal Revenue Service. Publication 946 (2025), How To Depreciate Property
3
Office of the Law Revision Counsel. 26 USC 168 – Accelerated Cost Recovery System
4
Internal Revenue Service. Publication 527, Residential Rental Property
5
Internal Revenue Service. Topic No. 704, Depreciation
6
Internal Revenue Service. About Form 4562, Depreciation and Amortization
7
Internal Revenue Service. Treasury, IRS Issue Guidance on the Additional First Year Depreciation Deduction Amended as Part of the One, Big, Beautiful Bill
8
Internal Revenue Service. Income and Expenses 7
9
Internal Revenue Service. Publication 544 (2025), Sales and Other Dispositions of Assets