Component reference · Pub 5653 + Rev. Proc. 87-56

UPS and PDU cost segregation

Centralized UPS, rack-mount UPS, battery strings, PDU and branch electrical distribution, transfer switches, dedicated backup generators — engineering-method classification under Rev. Proc. 87-56 and IRS Pub 5653. 5-year MACRS personal property vs. 39-year building-shell electrical service.

Why UPS classification is the densest reclassification component in a data center

UPS systems (8–15% of basis) plus PDU and branch electrical distribution (5–10% of basis) typically represent the single highest-density reclassifiable category in a data center cost-segregation study — often 13–25% of basis combined sitting in 5-year MACRS personal property that default 39-year straight-line treatment would miss entirely.

The classification distinction: UPS, PDUs, and IT-load-dedicated electrical distribution are process power for the facility (continuous, conditioned, redundant power to IT equipment) rather than building-shell electrical service (utility service entry, main switchgear, panelboards serving general-purpose loads like lighting and HVAC). Rev. Proc. 87-56 asset class 57.0 treats process power as 5-year MACRS personal property; building-shell electrical service stays 39-year MACRS.

Combined with 100% bonus depreciation restored permanently under OBBBA (PIS after January 19, 2025), the UPS + PDU carveout on a $15M enterprise on-prem DC typically surfaces $1.4M+ first-year deduction — and Form 3115 §481(a) catch-up captures the same depreciation on facilities placed in service 2017–2024.

UPS / power-distribution classification

Per Rev. Proc. 87-56 asset class table and IRS Pub 5653 component analysis. Classification turns on dedication — equipment serving IT-load process power qualifies as 5-year personal property; equipment serving general building-shell electrical service stays 39-year.

5-year MACRS personal property

Equipment-specific / facility-process-specific power equipment. Eligible for 100% bonus depreciation under §168(k) per OBBBA (PIS after 1/19/2025).

Component Basis share
UPS systems (centralized + rack-mounted)
Uninterruptible power supply, dedicated to facility process
 8–15%
PDU and branch electrical distribution
Equipment-specific power distribution (vs. building-shell wiring)
 5–10%
Backup generators (interior, dedicated)
When dedicated to facility process; exterior pad-mounted may classify differently
 3–7%
UPS battery strings (lead-acid VRLA, lithium-ion)
Treated with UPS as unitary system; replacement strings capitalize on subsequent replacement cycles
included in UPS
Transfer switches / ATS (IT-load dedicated)
Automatic / static transfer switches serving IT-load circuits
1–2%
In-cabinet PDUs (rack-mount, metered, switched)
Server, Vertiv, Raritan equipment-level distribution
1–3%

15-year MACRS land improvements

Power components physically located outside the building shell, on the site.

Pad-mounted exterior generators + fuel storage
 1–3%
External transformer pads, site switchgear
 2–4%

39-year MACRS building shell

Building-shell electrical service not dedicated to IT-load process power.

Base-building electrical (life safety, exterior lighting)
 3–6%
Utility service entry, main switchgear, general-purpose panelboards
Building-shell electrical service common to all building tenants / uses
2–4%

Per IRS Cost Segregation Audit Techniques Guide (Pub 5653, Chapter 7) and Rev. Proc. 87-56 asset class 57.0 framework. Engineering analysis per facility documents whether each power component is dedicated to IT-load process power (5-year personal property) or building-shell electrical service (39-year shell).

Worked example: $15M enterprise DC, UPS + PDU carveout

Illustrative; $15M enterprise on-prem DC, ~3MW IT load, C-corp held, placed in service 2025 (100% OBBBA bonus). UPS + PDU + dedicated electrical distribution carveout — full-facility cost-seg engagement surfaces additional deductions on cooling, racks, security, fire suppression beyond what's shown here.

Facility
Enterprise on-prem DC, ~3MW IT load, C-corp held
Depreciable basis
$15,000,000
Centralized UPS + battery strings (5-yr)
~10% = $1,500,000
PDU + branch electrical (5-yr)
~7% = $1,050,000
Transfer switches + in-cabinet PDUs (5-yr)
~3% = $450,000
Year-1 deduction (UPS / PDU only)
~$3,000,000 (100% OBBBA bonus on 5-year MACRS)
Estimated federal tax savings (UPS/PDU)
~$630,000 at 21% corporate rate

Assumes 21% federal corporate marginal tax rate at the C-corp filing entity. UPS / PDU carveout shown for illustration; the full-facility cost-seg engagement adds cooling, racks, security, fire suppression and typically reaches 45–55% total reclassification. Verify with your tax department before filing. State conformity to §168(k) varies.

UPS / PDU cost segregation questions

Is a centralized UPS system 5-year MACRS personal property or 39-year building shell?
Centralized UPS systems (Eaton 93PM, Schneider Galaxy VL, Vertiv Liebert, Mitsubishi 9900 — and similar enterprise/hyperscale-grade equipment) are 5-year MACRS personal property under Rev. Proc. 87-56 asset class 57.0. The UPS is removable, equipment-specific, and serves the facility process (IT load continuity) rather than building-shell electrical service. The IRS Cost Segregation Audit Techniques Guide (Pub 5653) addresses UPS classification explicitly — process-power-quality equipment dedicated to IT load qualifies as personal property when documented separately from base-building electrical infrastructure (utility service entry, main switchgear, panelboards serving general-purpose loads).
Are UPS batteries separately classified from the UPS itself?
Batteries can be classified together with the UPS module (5-year MACRS as a unitary system) or separately under specific circumstances. Most cost-seg engagements treat the UPS + battery system as a single 5-year MACRS asset. Replacement batteries (lead-acid VRLA strings replaced every 4–7 years; lithium-ion modules replaced on different cycles) raise a separate question — are the replacement costs capitalized as a new 5-year MACRS asset or expensed as repairs? The answer depends on the tangible property regulations (Reg. §1.263(a)-3) and whether the replacement is a betterment / restoration / adaptation. Most enterprise tax departments capitalize battery replacements as new 5-year MACRS; verify treatment with your tax department before filing.
What about lithium-ion UPS vs. lead-acid VRLA — different depreciation treatment?
MACRS classification is the same for lithium-ion and lead-acid VRLA UPS systems — both are 5-year MACRS personal property under asset class 57.0 when dedicated to IT-load process power. Lithium-ion UPSes (typically with longer service life, smaller footprint, lower maintenance) and lead-acid VRLA UPSes (typically with shorter battery cycle life but lower upfront cost) follow the same depreciation framework. Replacement-cycle considerations differ between chemistries (lithium typically 10–15 years vs. VRLA 4–7 years for battery strings), which affects the timing of subsequent capitalization events — not the MACRS class of the original UPS investment.
What's the treatment for UPS in a leased colocation cage (lessee improvement)?
If you're a colocation TENANT and you install your own UPS / PDU equipment inside a leased cage, the UPS is your equipment and depreciates as 5-year MACRS personal property in YOUR depreciation schedule (not the colocation operator's). The IT equipment, racks, cabling, and supplementary power infrastructure you bring into the leased cage are not part of the building shell; they're your removable personal property. Qualified Improvement Property (QIP) rules under §168(e)(6) apply to interior, non-structural improvements you make to non-residential real property — relevant if you build out shell space into a fit-for-purpose cage, though most colocation tenants aren't doing structural buildouts of leased space. Coordinate with your tax department on the lessee-improvement allocation.
How are transfer switches and ATS (automatic transfer switch) classified?
Transfer switches and ATS dedicated to the facility process (switching IT-load between utility, UPS, and generator power) are typically 5-year MACRS personal property when documented as serving the facility process rather than building-shell electrical service. The classification turns on dedication — an ATS serving only IT-load circuits is personal property; an ATS serving the entire building (life safety + general-purpose + IT) may classify as 39-year building shell or split between classes per its function. Engineering analysis per facility documents which circuits the ATS serves; component cross-references to single-line diagrams support the classification on examiner review.
Are exterior pad-mounted generators 5-year or 15-year MACRS?
Exterior pad-mounted backup generators (located on a concrete pad outside the building shell, with fuel storage tanks and yard transfer switchgear) are typically 15-year MACRS land improvements under Rev. Proc. 87-56 asset class 00.3. The pad, the generator enclosure, the fuel storage, and the underground or above-ground fuel supply piping classify together as site improvements serving the facility process. Interior generators dedicated to IT-load (where the generator is inside the building shell, in a dedicated generator room) typically classify as 5-year MACRS personal property when the equipment is removable and equipment-specific to the facility process. Engineering analysis per facility based on physical location and dedication.

See pricing on the full data center cost-seg engagement.

UPS-only carveouts work, but the full-facility engagement (UPS + PDU + racks + cooling + fire + security) is where the real reclassification % lands. Published pricing for sub-$25M facilities + hyperscale floor at $49,995.

See DC vertical hub · cooling depreciation · server room · methodology