Why Cost Segregation Uses Old Investment Tax Credit Rules

Modern cost segregation operates under today's depreciation system, but some of its most important asset-classification principles trace back to the former Investment Tax Credit. That can seem strange because the ITC discussed in the Cost Segregation Audit Technique Guide was repealed in 1986. The connection exists because the definitions used to distinguish certain types of property did not simply disappear with the credit. The 2025 IRS Cost Segregation Audit Technique Guide explains that the legislative and judicial histories of asset classification, depreciation, and the Investment Tax Credit are closely related. Understanding that history helps explain why modern cost segregation engineers still analyze concepts such as tangible personal property, buildings, structural components, inherently permanent property, and the function served by installed systems.

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Key Takeaways

• Why does an old Investment Tax Credit matter to cost segregation today?
• How did former § 48 distinguish different types of property?
• How did the ITC rules become part of modern depreciation classification?
• What kinds of assets can require these historical classification tests?
• Why can't an engineer classify property from an asset name alone?
• How can classification affect an asset's recovery period?
• What should property owners remember about the old ITC rules?

Why Does an Old Investment Tax Credit Matter to Cost Segregation Today?

The answer begins with the definitions used in modern asset classification.

The ATG explains that the definitions of property for purposes of § 1245 and § 1250 are essential to determining eligibility under several provisions of the Internal Revenue Code. More specifically, Treasury Regulation § 1.1245-3 defines terms including “tangible personal property,” “other tangible property,” “building,” and “structural component” by reference to Treasury Regulation § 1.48-1. That regulation relates to former § 48 and the Investment Tax Credit.

Former § 48 was enacted in 1962 along with §§ 1245 and 1250. It provided an investment tax credit for eligible property. The credit itself is no longer the modern cost segregation benefit being analyzed, but the classification framework developed around eligible and ineligible property became important to determining what constitutes § 1245 property and § 1250 property.

That is the key distinction.

Cost segregation is not using an old credit to generate today's depreciation deductions. Instead, historical definitions and legal principles developed in connection with that credit continue to inform modern property classification.

This is why understanding cost segregation sometimes requires looking backward before applying today's depreciation rules.

How Did Former § 48 Distinguish Different Types of Property?

The former Investment Tax Credit created an important dividing line between property that could qualify for the credit and property that generally could not.

According to the ATG, eligible property included tangible personal property and certain other tangible property closely integrated into specified business activities. Land, buildings, structural components contained in or attached to buildings, and other inherently permanent structures generally were not eligible.

Treasury Regulation § 1.48-1(c), as described in the ATG, defines tangible personal property by excluding land and improvements such as buildings and other inherently permanent structures, including their structural components. At the same time, property such as production machinery, office equipment, refrigerators, grocery counters, testing equipment, display racks, shelves, and signs could constitute tangible personal property even when located within or attached to a building.

That distinction introduced a question that remains central to cost segregation:

Is the asset part of the building or its structural operation, or is it property that should be treated separately under the applicable classification framework?

The answer is not always obvious from appearance.

A piece of machinery can be attached to the ground and still fall within the tangible personal property analysis. Conversely, the fact that something can theoretically be moved does not automatically mean it is tangible personal property. The ATG's discussion of inherently permanent property makes clear that permanency requires a broader factual analysis.

This is one reason CostSegRx engineers analyze physical characteristics, installation, function, documentation, and the relationship of an asset to the property rather than relying on a simple movable-versus-fixed test.

How Did ITC Rules Become Part of Modern Depreciation Classification?

The connection became particularly important through Hospital Corporation of America v. Commissioner, 109 T.C. 21 (1997).

In HCA, the taxpayer classified certain hospital-related items as tangible personal property and used a 5-year recovery period. The IRS challenged a number of those classifications, arguing that the disputed items were structural components of the buildings. The Service also argued that the ITC tests used to distinguish § 1245 property from § 1250 property should not apply under ACRS and MACRS.

The Tax Court disagreed with that part of the government's position.

The ATG explains that the court concluded that precedent developed to determine whether property constituted eligible property for purposes of the ITC was also applicable when determining whether property constituted § 1245 property for ACRS and MACRS purposes.

The IRS subsequently issued Action on Decision 1999-008. According to the ATG, the Service acquiesced to HCA to the extent that the ITC definition of tangible personal property remained applicable under ACRS and MACRS. Importantly, the Service did not agree with all of the Tax Court's conclusions about whether the individual assets disputed in HCA were tangible personal property.

That distinction matters.

HCA did not establish that every asset claimed by a taxpayer automatically becomes § 1245 property. It reinforced the relevance of the historical classification framework.

CostSegRx has a separate article examining the Hospital Corporation of America cost segregation case. We will also dissect HCA individually later in this ATG Authority Series because its reasoning deserves treatment beyond the historical overview here.

What Assets Can Require These Historical Classification Tests?

The significance of the former ITC framework becomes clearer when looking at actual commercial property.

A building can contain obvious equipment, but it can also contain partitions, floor coverings, specialized lighting, signs, electrical infrastructure, plumbing, equipment supports, and other installed components whose treatment depends on more than their name.

The ATG explains that cost segregation studies may classify items such as carpeting, wall coverings, partitions, millwork, and lighting fixtures as § 1245 property in some circumstances, but specifically cautions that these items may or may not constitute § 1245 property depending on the facts and circumstances for which the project was designed.

The former ITC rules themselves contained distinctions involving these types of assets. The ATG's discussion of the Revenue Act of 1978, for example, identifies certain special lighting, removable floor coverings, carpeting, removable partitions, ornamental fixtures, and similar property as examples relevant to the tangible personal property analysis.

But these examples should not be converted into a checklist saying that every carpet, partition, light fixture, or decorative element receives the same classification.

The specific property still matters.

That is why CostSegRx engineers ask questions about function, construction, installation, permanency, and the relationship of the component to the building or business operation.

The historical framework provides the classification principles. Engineering establishes the facts to which those principles are applied.

Why Can't an Engineer Classify Property From an Asset Name Alone?

The ATG repeatedly demonstrates why asset names are insufficient.

Electrical distribution systems are a useful example. An electrical system may serve the operation and maintenance of the building, specific equipment, or both.

The ATG explains that, following HCA and earlier cases, cost segregation methodologies used to distinguish ITC property from structural components can also be relevant when segregating § 1245 property from § 1250 property. It specifically notes that an asset does not necessarily have to be exclusively one or the other in every analytical context.

In Scott Paper Co. v. Commissioner, the court focused on the ultimate uses of electrical power. The ATG explains that power used for general building operation and maintenance was distinguished from power used to operate qualifying machinery and production processes. That analysis became known as the functional allocation approach.

Later cases addressed that approach, including Illinois Cereal Mills and Morrison. The ATG notes that Morrison adopted the Tax Court's focus on the ultimate use of electricity distributed by the primary electrical systems.

This is exactly why CostSegRx emphasizes function before classification.

An engineer looking at conduit, wiring, panels, or branch circuits should not classify the system merely because it is “electrical.” The engineer needs to understand what the system serves.

The same principle extends beyond electrical systems. A physical description tells us what something looks like. Engineering analysis helps establish what it actually does.

How Can Classification Affect an Asset's Recovery Period?

Illustrative example only. Figures shown are estimated for demonstrative purposes only. Actual classifications, recovery periods, depreciation deductions, and tax results depend on the specific assets, property facts, engineering analysis, applicable tax authority, and taxpayer circumstances.

Assume a commercial project contains $150,000 of installed components that require analysis to determine whether they are part of the building or qualify for treatment as tangible personal property.

The engineering team should not begin by deciding that the $150,000 should receive accelerated depreciation.

Instead, the team evaluates the actual components.

Suppose the facts and applicable classification framework support treating $60,000 of those components as 5-year property while the remaining $90,000 is properly included in 39-year nonresidential real property.

The important lesson is not the amount of depreciation generated in a particular year. The lesson is why the $60,000 and $90,000 are treated differently.

The answer must come from the assets and the applicable classification rules.

Historical ITC principles can help establish the legal framework for distinguishing tangible personal property from buildings and structural components. Engineering establishes the physical and functional facts. Modern depreciation rules then determine the applicable recovery treatment.

Changing the assumed percentages without changing the underlying property facts would not be an engineering methodology.

What Should Property Owners Remember About the Old ITC Rules?

The former Investment Tax Credit matters to modern cost segregation because the classification framework developed around it did not simply disappear when the credit was repealed.

The ATG explains that property allocations and reallocations are typically based on criteria established under the ITC laws of § 48 and that the history includes numerous legislative acts, court decisions, Service rulings, and a lack of bright-line tests.

HCA strengthened the connection by holding that precedent developed for determining qualifying ITC property was relevant to distinguishing property under ACRS and MACRS, with the IRS later acquiescing to the continued applicability of the ITC definition of tangible personal property.

For property owners, the practical lesson is straightforward.

Old rules do not mean outdated analysis.

They are part of the legal history behind today's classification framework. But that history still has to be applied to the actual property.

CostSegRx engineers therefore begin with the physical facts: what the asset is, what it does, how it is installed, what it supports, and what the documentation shows. The applicable tax framework then determines how those engineering facts affect classification.

The rules provide the classification framework. The property provides the facts. Engineering connects the two.