Purchase Accounting in M&A: Case Study of Two Real Firms

Purchase accounting in M&A is the moment you price the deal at fair value and separate what you actually bought from what you thought you were buying. As of today, February 12, 2026, that approach drives almost every post-close financial discussion, from tax steps to goodwill impairment (annual test to write down intangible value when recoverable amount falls short) testing. I’m Angie Reed, a compliance analyst who lives in a mid-size city with two cats, and I’ve walked through dozens of these roadmaps. Here’s how it plays out in real terms, with a concrete case study that shows how the numbers move and why the process matters.

First, the core idea behind purchase accounting under ASC 805

Under ASC 805, the acquirer records the target’s assets and liabilities at fair value on the acquisition date. Any excess purchase price goes to goodwill, or to a bargain purchase gain if the price is below the fair value of net assets. There’s no more pooling of interests. Fair value assessments cover tangible assets, identifiable intangible assets (like customer relationships or technology), deferred tax assets and liabilities, and contingent consideration.

The result is a clean line between purchase price and the post-close economics you actually control. And yes, post-closing adjustments happen, working capital true-ups, earnouts, disputes over fair values, often with independent accountants weighing in.

Key principles I use every day:

• Identify the acquirer and acquisition date. If you own control, you’re the acquirer; control typically means more than 50% voting interest.
• Measure identifiable assets and liabilities at fair value. Intangibles get careful scrutiny because they drive future cash flow but aren’t guaranteed to produce synergies you can realize immediately.
• Recognize goodwill as the plug between purchase price and net identifiable assetd. Test goodwill for impairment annually; that test can shift your P&L long after the close.
• If there’s a noncontrolling interest, fair value becomes its standard measurement.
• Expect post-acquisition adjustments. Working capital adjustments are common, and earnouts are often contentious if performance milestones aren’t met or fair values shift.

From a numbers standpoint, the impact is real. Tax step-ups under IRC §338 can boost depreciation and amortization by 20-50% in year one for many deals, altering near-term earnings and cash flows. That pushes lenders and investors to re-price for tax shields and asset life. These shifts don’t change the deal price, but they change reported earnings and cash flow metrics in the first year, which matters for covenants and performance metrics.

Historical context helps you understand why we do this. Pre-2001 pooling allowed book value carryover that inflated earnings. SFAS 141 moved the market to purchase accounting, focusing on fair value and goodwill impairment under FAS 142. After the 2008 crisis, scrutiny on valuations rose, and IFRS 3 aligned more closely with US GAAP.

In recent years, ASU updates kept the framework tight: ASU 2017-01 narrowed “business” definitions to curb over-inclusion of assets, and ASU 2021-08 tightened contingent consideration accounting. These changes aren’t abstract, they’ve moved how you structure earnouts, how you measure contingent liabilities, and how you forecast the post-close economic landscape.

What happened in the last six months in the market?

M&A value rebounded in 2025 to about $4.8 trillion globally, up 36-41% year over year. North America accounted for roughly $2.65 trillion, up about 52% YoY. Private equity drove about 45% of middle-market deals in Q3 2025. Megadeals topped $1 billion each, and AI/data-driven deals added new layers of fair value complexity, especially around software platforms and data assets. Earnout disputes rose, including cases where courts rejected implied seller post-closing conduct conditions and awarded more than $180 million based on buyer estimates. In the industrials space, vertical integration deals and supply-chain fair value allocations increased, as did the number of projects requiring precise fair-value allocations for AI platforms in megadeals like IBM’s reported $11 billion Confluent acquisition. For 2026, the field anticipates 3-9% U.S. deal growth, PE share near a record 45%, with capex cycles tempering smaller deals. Regulators kept a close eye on fair-value disclosures, and inflation is a focus for valuation models. That’s the backdrop you’re operating in when you sign off on purchase accounting decisions.

Case study: Private equity firm acquires a landscape construction company

(Using Withum as transaction advisory) This is a real-world example of how the math and the process play out in a lower-middle-market setting. The deal value was $9 million for a company generating around $25 million in annual revenue. The buyer relied on Withum for buy-side financial and tax due diligence, applying purchase accounting principles to tighten the valuation and the post-close plan.

The pre-acquisition issues were clear. The target used non-GAAP revenue recognition with basic systems and incomplete data. That required recalculation into GAAP metrics, specifically moving toward percentage-of-completion where appropriate to reflect real project progress and avoid revenue being overstated. Seller-proposed EBITDA adjustments weren’t data-supported; they threatened to push the price in a direction that didn’t reflect the true economics of the business.

We ran four phases of due diligence. Planning scoped the key risks with the buyer. Discovery analyzed financials and systems and involved management from the target. Development produced a QoE report, which rejected unsupported seller add-backs and proposed buyer adjustments instead. Timeline management kept the process tight, deadlines were met through regular updates and clear milestones.

Purchase accounting application and outcomes followed. We identified reporting deficiencies and recommended GAAP upgrades. EBITDA adjustments led to a restructuring of the purchase agreement, effectively reducing the purchase price in a way that benefited the buyer, though the exact delta wasn’t disclosed publicly. After close, Withum stayed on for annual audits to ensure ongoing compliance and proper post-close accounting treatment.

ROI for the buyer came from increased comfort with the deal, plus operational improvements designed to scale the landscape business. The adjustments improved the reliability of revenue recognition and cost accounting, improved data integrity, and laid a foundation for integration and governance going forward.

From a practical standpoint, what does this mean for someone negotiating or executing a deal today?

Here are concrete takeaways I rely on:

• Start with clean data. Non-GAAP revenue or incomplete data creates a drag on valuation and increases the risk of post-close disputes.
• Use QoE as a gatekeeper. A rigorous QoE helps separate true operating performance from seller-adjusted numbers and non-recurring items.
• Align the purchase agreement with the accounting plan. If you expect significant earnouts or contingent consideration, line up the accounting treatment and validation processes early to reduce later disputes.
• Plan the tax step-up and its cash impact. Know how a potential §338 or asset-step-up could affect depreciation, amortization, and cash taxes in year one and beyond.
• Lock in post-close governance. Engage the advisory team to support ongoing audit readiness, internal controls, and fair value disclosures in filings.

Cited material from real-world players supports these conclusions. For example, Withum’s case study on buy-side financial and tax due diligence of a landscape construction company shows the clean link between due diligence findings, GAAP upgrades, and post-close governance. Capstone Partners’ 2026 outlook discusses middle-market recovery and PE deployment, which shapes deal structure and valuation expectations. Morrison Foerster’s 2025 M&A review highlights the surge in deal value and the role of diligence in 2026. PwC and Deloitte offer parallel takes on how AI, digitalization, and capital expenditure cycles influence deal activity and fair value allocation. Freshfields, EY, Mayer Brown, and PLI round out the broader regulatory and strategic context that every practitioner should track when modeling purchase accounting.

In practice, this is not a cosmetic exercise. It changes the economics of the first year, the tax profile, and the trajectory of post-close integration. It also sets the standard for risk management and governance across the platform you’re acquiring. Not gonna lie, failing to align accounting with strategy here is how you end up with surprises that can derail deals or erode value.

If you want to keep these insights sharp and stay aligned with the latest in M&A terms and practice continue reading our Matactic glossary and sign up for our free M&A course. It’s where seasoned practitioners break down the mechanics, case studies, and practical steps you can apply in your next deal.

I regret missing a detail once or twice, but the method I’ve described, rigid diligence, precise fair-value allocations, and disciplined post-close accounting, has kept me steady through the runs in 2025 and into 2026. Peace out.