---
title: "What Is Material Adverse Change (MAC)?"
term: "Material Adverse Change (MAC)"
description: "Material adverse change (MAC) is a contract clause allowing a buyer to walk away from a deal if the target suffers a significant negative change in business, assets, or prospects before closing."
date: 2026-07-25T00:00:00.000Z
updated: 2026-07-25T00:00:00.000Z
topics: ["venture-capital"]
source: https://venturecapitaltracker.com/glossary/material-adverse-change-mac
---

# What Is Material Adverse Change (MAC)?

> Material adverse change (MAC) is a contract clause allowing a buyer to walk away from a deal if the target suffers a significant negative change in business, assets, or prospects before closing.

**Material adverse change (MAC)** is a provision in acquisition and financing agreements that permits a party—usually the buyer—to terminate the transaction if the target experiences a materially harmful change before closing.

### How it works

After signing a merger or purchase agreement, weeks or months may pass before closing while regulators approve and conditions are satisfied. During that gap, the seller must operate in the ordinary course.

If business deteriorates significantly—losing a top customer, a product failure, litigation, or accounting restatement—the buyer may claim a MAC occurred and refuse to close. Courts and negotiators distinguish:

- **Company-specific MAC:** Target uniquely harmed
- **Excluded events:** General economic downturns, industry-wide shocks, pandemics (often carved out post-2020)
- **Disproportionate impact:** Target hurt worse than peers

MAC definitions are heavily negotiated. Sellers push narrow MAC and broad carve-outs; buyers want flexibility when diligence surprises emerge late.

### Why it matters

- **Founders:** Run the business as if the deal might fail until money hits the account. Major pivots or risky bets pre-close invite MAC claims.
- **Investors:** As buyers, MAC is downside protection; as sellers of portfolio companies, weak MAC language exposes LPs to retrade risk.

### Common mistake

Assuming a signed LOI or merger agreement guarantees closing. MAC, financing conditions, and regulatory approval can still kill the deal.

### Related ideas

See also [merger](/glossary/merger), [letter of intent](/glossary/letter-of-intent), [closing conditions](/glossary/closing-conditions), and [ordinary course](/glossary/ordinary-course).

## FAQ

### What is MAC in simple terms?

It is legal language that lets the acquirer cancel the deal if something seriously bad happens to the business before signing closes—major customer loss, fraud, or a sharp downturn beyond normal market swings.

### Why does MAC matter?

Signed deals are not done until closed. Founders operating in the gap between sign and close face MAC risk if metrics collapse. Buyers use MAC negotiations to allocate pre-close risk.


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Source: https://venturecapitaltracker.com/glossary/material-adverse-change-mac