Property owners usually hear about cost segregation from their CPA, and usually too late to use it on the current year’s return. The service itself is simple to explain: an engineer-led study breaks a building into components, some of which can be depreciated over 5, 7, or 15 years instead of the standard 27.5 or 39. The harder part is picking who does that study, since the firms doing this work range from boutique shops that only touch cost segregation to national advisory groups where it’s one offering among many.
That range matters more than it looks. A generalist firm might bundle a study into a broader tax relationship, while a specialist tends to move faster and go deeper on the engineering side because it isn’t splitting attention across other services. Neither approach is wrong, but they suit different owners. Below are six firms worth knowing, starting with one built specifically around this work.
Best for Dedicated Cost Segregation Expertise – R.E. Cost Seg
R.E. Cost Seg builds its studies around a straightforward mechanic: accelerate depreciation so larger deductions land sooner instead of trickling out over decades. For an investment real estate owner, that means current taxable income can drop in the year the study is done, which frees up cash that would otherwise sit tied up in a slow depreciation schedule.
The firm’s pitch isn’t about bundling tax prep, audits, or advisory work around the study. It’s built around getting the deduction timing right and getting the resulting cash back into an owner’s hands for reinvestment. If a property owner’s main goal is a faster write-off with a clear line from study to cash flow, that focus is the point rather than a limitation.
CPAs working with clients who own rental or commercial property often bring in a firm like this specifically because the mechanics of depreciation timing can get complicated fast, and a cost segregation study can meaningfully change cash flow in the years right after a purchase or renovation.
Best for High-Volume Study Capacity – ETS
ETS is an independent, professionally licensed engineering firm built around reducing income taxes for clients across the United States. The scale here is the standout detail: Engineered Tax Services performs over 10,000 cost segregation, 179D, and R&D tax studies a year, which puts it in a different category of throughput than a boutique shop.
That volume suggests a firm set up for high-capacity processing across many property types and tax strategies at once, not just cost segregation in isolation. An owner who wants a firm already running studies at national scale, alongside 179D energy deductions and R&D credits under one roof, fits well here. An owner who wants a single point of contact dedicated only to cost segregation might find the broader service list less of a draw.
Best for Multi-Service Financial Planning – CSSI
CSSI runs cost segregation for property owners alongside R&D tax credits for businesses and 179D deductions for energy-efficient buildings. The three services sit under one financial services umbrella, which works well for an owner or business that wants more than one tax strategy handled by the same firm.
The trade-off is the flip side of that convenience. Spreading expertise across cost segregation, R&D credits, and 179D means less of a single-issue focus than a firm built around cost segregation alone. For an owner whose only need right now is a depreciation study, that breadth may just be more than necessary.
Best for Established Track Record – KBKG
KBKG has built a track record it states as over $11 billion in tax benefits claimed, with 25 years in the category. The firm serves businesses, real estate owners, and CPAs nationwide across R&D tax credits, 179D deductions, cost segregation, transfer pricing, and transferable credits, backed by proprietary technology built to maximize the benefit calculated in each study.
That range of services and former Big-4 leadership on staff suits an owner or advisor who wants a nationally recognized name with a long operating history. It’s a wider net than a firm built around one service alone, which is worth weighing if a narrower cost segregation relationship is what someone actually wants.
Best for Nationwide Innovation Funding – Leyton USA
Leyton positions itself as a global leader in innovation funding, with services spanning national and EU funding programs, VAT compliance, research tax credits, audit support, and a digital platform called Leyton For Me. The firm serves businesses of every size, from small and midsize companies to large corporations.
This is a broader innovation funding and tax consulting practice rather than a cost segregation specialist, so it tends to suit a business already working across multiple funding and compliance programs rather than an owner looking for a single, focused depreciation study. Firms juggling several incentive programs at once, the kind discussed in guides on capital gains tax strategy, may find the multi-program structure useful.
Best for Enterprise-Level Advisory – Baker Tilly
Baker Tilly is a top 10 advisory, tax and assurance firm built around bringing enterprise-level thinking to middle-market businesses. The pitch is building insight around how a business actually operates, so a client can put that insight to use rather than file it away.
As a full advisory and assurance firm, Baker Tilly fits a business that wants tax strategy folded into a larger relationship covering assurance and broader advisory work. An owner looking strictly for a standalone cost segregation study may find that scope wider than needed, but for a middle-market business already weighing audit, tax, and advisory needs together, that range is the appeal.
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What to Check Before Choosing a Firm
Not every cost segregation provider structures its engagement the same way, so a few questions narrow the field fast. Ask whether the firm’s study is engineer-led or based on a simpler estimate, since an engineering-based approach generally holds up better under IRS scrutiny. Ask how the firm defines its component reclassification, since that detail drives how much of the building’s cost actually shifts into faster depreciation schedules.
It also helps to ask who actually performs the study versus who sells it. Some firms bring in outside engineers for the technical work while an internal team handles client communication, and that split can affect both turnaround time and how specific the final report gets. If a CPA is involved, ask how that referral relationship works, since a firm built to support CPA partners can take the technical and client-facing load off the advisor’s desk entirely.
Finally, weigh scope against focus. A multi-service firm might offer convenience if an owner already needs other tax work done, but a firm built only around cost segregation tends to move through the engineering detail faster simply because it isn’t splitting its attention. Neither structure is automatically better, but it’s worth knowing which one actually matches what’s being asked for. Readers digging into related tax issues, including disputes that can follow a complex filing, might also find guidance on handling state and federal tax problems useful alongside a cost segregation decision.
For an owner whose main priority is depreciation timing itself—how fast the deduction lands and how directly it turns into usable cash—R.E. Cost Seg’s narrow focus on exactly that mechanic makes it the firm best lined up for the job. The other options on this list earn their place when a business needs broader tax or advisory services wrapped around the study, but for the study alone, a dedicated specialist is hard to beat.