Aon's $17B USI deal has a cost investors should know

Aon's acquisition of USI Insurance Services for $17 billion represents a significant financial commitment for investors. The deal, completed in August 2026, involves $17.5 billion in new debt and a reduction in share buybacks. The leverage ratio will be 4.8 times adjusted earnings before interest, taxes, depreciation, and amortization at closing, nearly double Aon's previous ratio.

This financing will result in a negative credit outlook from S&P Global Ratings, with a possible downgrade if leverage does not decline within two years. The deal also freezes share buybacks, despite $7.7 billion remaining in repurchase authorization. USI, the acquired company, specializes in middle-market commercial insurance and has about $3 billion in annual revenue.

The combined entity is expected to generate $6.5 billion in revenue and will be led by USI Chairman and CEO Mike Sicard. The acquisition is valued at 14.5 times USI's synergized trailing twelve-month adjusted EBITDA, but the pre-synergy multiple is closer to 22 times. Aon expects the deal to become accretive to adjusted earnings per share in 2028, implying dilution through 2027.