It’s a safe bet that partners at Simpson Thacher & Bartlett aren’t lying awake at night worrying about their 401(k)s. No matter what happens to the stock market, they’re guaranteed to retire rich, thanks to the firm’s pension plan.

The plan—the most generous among 21 Am Law 100 pension plans we analyzed for this article—promises retired partners a quarter of the compensation they received during their highest-earning years. For life. On top of that, retirees receive an additional payout of 130 percent of that highest-compensation average, spread out over seven years. Currently, 30 retired Simpson partners are receiving these pension benefits.