The 7 Best Cost Segregation Companies for Scalable, Audit-Ready Studies

A while back, I was brought into a portfolio review for a group that owned student housing across three university markets. On paper, they had “done cost seg” on most of their assets. In reality, they had a patchwork of studies: one from a local engineer, one from a regional CPA firm, and one from a national provider that reused the same template for every building.

When we lined the reports up side by side, parking structures were treated three different ways. Interior common areas were sometimes short-life, sometimes long-life, and sometimes not broken out at all. The numbers were defensible individually, but almost impossible to explain as a coherent strategy to lenders and investors.

That review reinforced why choosing the right partner matters. The best cost segregation companies solve for precision and consistency across the portfolio, not just a single impressive deduction in year one.

Rapid Shortlist: 2026’s Best Cost Segregation Companies

1. RE Cost Seg: Best for Consistent, Portfolio-Grade Studies

• Standardized methods across assets
• Built for multi-year planning
• Strong support for CPAs and lenders

2. KBKG: Best for Complex, Multi-State Filings

• Deep state and federal coordination
• Scales across mixed asset types
• Strong technical and tax depth

3. Madison SPECS: Best for Investor-Ready Reporting

• Clear, investor-facing summaries
• Detailed, audit-ready schedules
• Helpful upfront feasibility reviews

For a full breakdown of each firm, how they differ, and when to use which, continue into the detailed reviews below.

How To Pressure-Test A Cost Segregation Firm

1. Clarify The Business Problem They Are Solving

Before fees or timelines, it should be obvious that the provider understands why the client is doing the study now. Exceptional firms tie the engagement to specific business triggers such as an upcoming refinance, a recapitalization, or a shift in investor expectations. If the conversation stays generic, results usually will too.

Key questions to ask:

• What is the main decision this study is meant to support?
• How will you reflect that in the way you structure the report?
• How would your approach differ if we were selling in three years versus holding for ten?
• What information do you need from our side to tailor the engagement?

2. Examine Their Documentation And Governance Standards

Good depreciation outcomes are not enough if the underlying work cannot be explained in five years. Strong providers have clear internal policies, standard templates, and a predictable way of documenting assumptions. That consistency is what makes portfolio-level defense possible.

Look for signs of discipline:

• Standard report structure across different assets
• Clear asset descriptions, not vague catch-all labels
• Written methodology notes that explain key judgments
• Defined internal review steps before a report is released

3. Match Their Capacity To Your Deal Flow

Some firms are excellent on a single complex property but struggle to keep pace once acquisition volume ramps up. Others are designed for throughput but less suited to one-off, highly specialized projects. The right fit depends on how many deals and projects are realistically coming over the next few years.

Topics to cover up front:

• How many studies can they run in parallel for one client
• Typical turnaround time for different property types
• How do they prioritize work if several assets come in at once
• Whether they can assign a stable core team across multiple projects

4. Validate How They Support CPAs, Lenders, And Investors

The technical study is only useful if the people who rely on it can apply it. The best firms are comfortable speaking with external CPAs, walking lenders through key points, and helping owners explain results to investment committees. That external-facing capability is often what separates “good work” from “work that actually moves decisions.”

Signals of a strong support model:

• Willingness to speak directly with the CPA or tax department
• Ability to provide short summaries for lender or IC materials
• Clear point of contact for post-delivery questions
• Defined process for addendums or clarifications if a third party raises issues

Detailed Reviews Of 7 Leading Cost Segregation Companies

1. RE Cost Seg: Best for Consistent, Portfolio-Grade Studies

• Founded: 2022
• Headquarters: Houston, TX

Why RE Cost Seg is the best cost segregation company:
RE Cost Seg focuses on delivering consistent, engineering-backed studies that can be replicated across an entire portfolio. The firm starts by mapping a client’s acquisition pace, renovation plans, and financing milestones, then designs engagements so the timing of depreciation supports those realities. That means aligning studies with key events such as refinances, recapitalizations, or major capex cycles rather than treating each asset as an isolated project.

Their reports use a standardized structure that asset management, finance, and external CPAs can work with easily: clear asset categorizations, separated land improvements, and methodology notes that make future defense and replication straightforward. RE Cost Seg is particularly well-suited to owners and sponsors who want every new asset to plug into a consistent depreciation playbook, not a different approach each time a study is ordered.

2. KBKG: Best for Complex, Multi-State Filings

• Founded: 1999
• Headquarters: Pasadena, CA

KBKG is structured for owners with tax exposure across several states, where differences in depreciation conformity can complicate planning. Its cost segregation practice pairs engineering-driven analysis with tax professionals who understand how federal decisions will flow through to state returns and estimated payments.

The firm is comfortable working across a mix of property sizes and types, and it offers tools and processes that help standardize methodology even when the portfolio spans multiple jurisdictions. For businesses that file in many states or operate under complex entity structures, KBKG brings the coordination and technical depth needed to keep depreciation decisions coherent rather than fragmented.

3. Madison SPECS: Best for Investor-Ready Reporting

• Founded: 2004
• Headquarters: Lakewood, NJ

Madison SPECS is oriented around active investors who need cost segregation results that can be communicated clearly to partners and capital providers. The firm typically begins with a feasibility review, giving sponsors and owners a realistic view of potential benefits before they commit.

Its studies are packaged with both investors and CPAs in mind. Executive-friendly summaries outline the impact on cash flow and returns, while detailed schedules and supporting documentation equip tax teams for implementation and audit support. For syndicators, funds, and joint ventures that need to translate technical outcomes into investor language, Madison SPECS offers a reporting style that travels well between those audiences.

4. Engineered Tax Services: Best for Engineering-Led Technical Depth

• Founded: 2001
• Headquarters: West Palm Beach, FL

Engineered Tax Services operates as a licensed engineering firm with a strong focus on technically complex assets. Its teams routinely handle properties with significant mechanical, electrical, and specialty systems, which makes the firm a good fit for healthcare, hospitality, laboratory, and other infrastructure-heavy projects.

Field verification, blueprint analysis, and detailed component mapping sit at the center of ETS’s methodology. The resulting reports include thorough narrative explanations and supporting workpapers, which help clients with higher audit visibility or more formal risk frameworks. Owners who value deep engineering rigor and fully articulated reasoning behind each classification will find ETS aligned with that expectation.

5. CSSI: Best for Large, Distributed Portfolios

• Founded: 2000
• Headquarters: Baton Rouge, LA

CSSI (Cost Segregation Services, Inc.) is designed to support portfolios with many properties spread across multiple markets. The firm has completed a high volume of studies nationally and has built internal processes that allow it to run numerous projects in parallel while maintaining consistent methods.

For rollup strategies, franchise systems, or operators adding locations regularly, CSSI can help identify where studies will produce the most value and then execute those studies at scale. Its standardized approach to documentation and classification makes it easier for finance and tax teams to track and defend depreciation positions across dozens of assets, not only a select few marquee properties.

6. Cost Seg EZ: Best for Smaller Owners and First-Time Users

• Founded: 2015
• Headquarters: Princeton, NJ

Cost Seg EZ is aimed at owners who need professional-grade cost segregation without the complexity or price point of a large-firm engagement. Its process is intentionally streamlined: a clear intake, defined data requirements, and simple pricing tiers that make it easy for a smaller investor or operator to decide when a study makes sense. That accessibility is particularly useful for those moving from a handful of properties into a more deliberate tax strategy.

The firm offers options that range from lighter-touch studies for straightforward assets to fully engineered work for higher-value or more nuanced properties. Reports are concise and implementation-focused, so outside CPAs can plug the results directly into their tax work. For first-time users and smaller portfolios that still want to do things correctly, Cost Seg EZ functions as an approachable entry point into cost segregation without sacrificing core quality.

7. CohnReznick: Best for Institutional-Scale Real Estate Platforms

• Founded: 1919
• Headquarters: New York, NY

CohnReznick brings cost segregation into a broader suite of tax, assurance, and advisory services aimed at institutional real estate platforms. Its teams are accustomed to working with REITs, funds, and large operators that manage multi-entity, multi-jurisdiction portfolios under strict governance and reporting requirements. Cost segregation work is scoped and delivered with that environment in mind, so methodology, documentation, and controls align with internal policies and external scrutiny.

Because cost segregation sits beside transaction advisory, federal and state tax planning, and fund-level structuring, the firm can coordinate depreciation strategy with capital formation, exits, and ongoing investor communication. For organizations that need cost segregation to fit neatly into a larger compliance and reporting architecture, CohnReznick offers depth, scale, and a level of process maturity that matches institutional expectations.

Turning Cost Segregation Into A Stable Part Of The Playbook

For most owners, the real risk is not whether a single study was done correctly, but whether the overall position makes sense when lenders, investors, or auditors look across the portfolio. The firms in this guide stand out because they combine technical depth with structure. They have defined methods, clear documentation, and enough capacity to keep pace with real-world deal flow.

Choosing among the best cost segregation companies should come down to fit: how well a provider understands the business problem, how easily their work plugs into existing tax and reporting processes, and how reliably they can repeat that quality as the portfolio evolves. When those pieces are in place, cost segregation stops being an occasional project and becomes a stable lever in long-term real estate strategy.