Comfort Systems USA pairs exceptional AI-infrastructure growth and a $14.06 billion backlog with elite margins, but its 42x-plus P/E leaves long-term returns vulnerable to multiple compression.
Overview
Comfort Systems USA is a national mechanical, electrical, and plumbing installation and maintenance provider operating through 50 decentralized companies across more than 206 locations in 150 cities. Mechanical Services contribute approximately 72% of year-to-date revenue and Electrical Services 28%, with technology customers now accounting for 57.6% of revenue and advanced manufacturing 17.5%. **The company is benefiting from AI data-center cooling intensity, electrical infrastructure demand, and industrial reshoring.** Q2 2026 revenue rose 50.3% year over year to $3.27 billion, operating income increased 86.1% to $558.0 million, operating margin expanded 330 basis points to 17.1%, and diluted EPS rose 91.9% to $12.53, beating consensus by $2.08. Backlog reached a record $14.06 billion, up 73% year over year. The balance sheet held $1.85 billion of cash against only $54.1 million of debt. Management raised 2026 same-store revenue growth guidance to the mid-to-high 30% range, although second-half growth is expected to decelerate to the high-20% to low-30% range. The stock’s strategic quality is offset by a 42.51x–43.62x trailing P/E and long-term multiple-compression risk; catalysts include Hunt Electric integration and modular-capacity expansion.