Goodwill and Purchase Accounting in M&A Models

Merger models are not just "add the income statements and divide by new shares." Purchase accounting sits underneath. The acquirer writes assets and liabilities up (or down) to fair value, plugs goodwill for the residual, and then lives with extra D&A that can turn an accretive deal dilutive. If you can walk goodwill and the step-up without a template, you are ahead of most superday candidates.

The deal value bridge (simplified)

Equity purchase price (offer price × diluted shares)
+ Net debt assumed (or refinanced)
= Enterprise value paid

Fair value of identifiable net assets
= Book equity ± fair value adjustments to assets/liabilities
  (inventory, PP&E, intangibles, deferred revenue, etc.)

Goodwill = Enterprise value paid − Fair value of identifiable net assets

Exact mechanics vary with stock vs cash, deferred tax on step-ups, and whether you are looking at equity value vs enterprise value. The interview version is: price paid above fair value of identifiable net assets becomes goodwill.

Why this residual exists

You paid for things that are not on a clean identifiable list: assembled workforce, growth options, control premium, expected synergies. Accounting does not let you capitalize "synergies" as a neat asset line the way students sometimes want, so the residual lands in goodwill.

Asset step-ups and the earnings drag

Accretion/dilution interviews love a deal that looks accretive before PPA and dilutive after. The step-up D&A is the reason.

Worked numeric walkthrough

Acquirer pays $1,000M equity for a target with $400M book equity and $200M net debt. EV paid = $1,200M.

Identifiable assets get a $150M step-up (PP&E + intangibles). For a clean interview plug:

EV paid                              $1,200
− Fair value identifiable net assets   $850
= Goodwill                             $350

If $100M of the step-up amortizes straight-line over 10 years, that is $10M of extra annual D&A. At a 25% tax rate, after-tax drag is $7.5M. On 50M pro forma shares, that is $0.15 of EPS pressure every year until the intangible is gone.

Synergies have to clear that bar before the deal is accretive on an EPS basis.

Inventory step-up timing

Inventory write-ups hit quickly as product sells through. That can make the first one or two quarters look worse on GAAP gross margin even if the strategic deal is fine. Mention this if they ask why Year 1 optics are noisy.

Cash vs stock and why people get confused

Purchase accounting happens whether you pay cash or stock. The financing mix changes EPS math (new shares vs interest expense), not whether you revalue the target.

What changes with consideration:

• Cash deal: more interest expense or less cash interest income; share count may not rise
• Stock deal: share count rises; interest may not
• Mixed: both

Goodwill is about price vs fair value, not about cash vs stock.

Deferred taxes (high level)

Writing assets up without a matching tax basis creates a deferred tax liability in many cases. That DTL is part of the purchase accounting entry and can affect goodwill. Many interview cases skip this. If they bring it up, say:

"Step-ups can create temporary differences. Accounting often recognizes a DTL at the tax rate times the taxable temporary difference, and that affects the goodwill plug."

Keep it short unless they push. Getting the idea right matters more than perfect ASC mastery in an undergrad interview.

Where this shows up in a pitch book or model

• Sources and uses: purchase equity, refinance debt, fees
• Opening balance sheet: goodwill, stepped-up assets, DTL
• Income statement: synergy ramp, incremental D&A, interest
• EPS: net income ÷ diluted pro forma shares

If the MD asks why Year 1 is dilutive and Year 2 is accretive, a clean answer is: Year 1 carries full step-up D&A and only partial synergy realization; Year 2 has more synergies against the same amortization run-rate.

Common mistakes

30-second interview answer

"We allocate purchase price to fair value of identifiable assets and liabilities, then plug goodwill as the residual. Step-ups on PP&E and intangibles create extra D&A that hits EPS. Goodwill itself is not amortized under US GAAP. When I run accretion/dilution I include the after-tax step-up D&A and the synergy ramp, because leaving PPA out makes almost every deal look better than it is."

Follow-up drills

1. If step-up amortization rises by $20M pre-tax at 25% tax, what is the after-tax EPS hit on 100M shares?
2. If synergies are $30M pre-tax with the same tax rate, do they clear that amortization hit?
3. What happens to goodwill if identifiable intangibles are written up more (holding EV paid fixed)?
4. Why might Year 1 GAAP accretion differ from Year 2?

Answers sketch:

1. After-tax hit $15M → $0.15 EPS
2. After-tax synergies $22.5M → yes, clears $15M amortization hit before other costs
3. Goodwill falls because more value is assigned to identifiable assets
4. Synergy ramp and inventory step-up timing

How this connects to accretion shortcuts

The all-stock P/E shortcut ignores purchase accounting. That is fine for a 20-second directional answer. It is not fine as your final answer if the interviewer asks about Year 1 GAAP EPS. A deal can be "accretive on the P/E rule" and still dilutive in Year 1 after step-up amortization and incomplete synergy realization.

Strong candidates stack the layers:

1. Directional P/E or earnings-yield shortcut
2. Financing mix effects (shares vs interest)
3. Synergies and costs to achieve
4. PPA / step-up D&A
5. Timing (Year 1 vs Year 2)

Practice

Build a merger model that grades goodwill, step-up amortization, and pro forma EPS in the same case. Once you have seen the residual math on a live sheet, the whiteboard version stops feeling abstract. Harborview-style M&A cases are built around exactly that linkage between purchase accounting and accretion.