Making partner isn't cheap, and the cost is more than just the years of hard work and stress that associates put in as they reach for the brass ring.

Newly minted partners face real financial expenses as they change their job title. Some of those costs are related to their new status as owners of the firm instead of employees: Now they must pay the entire cost of benefits and quarterly estimated income taxes. There's also the capital contribution required by many firms, which represents the so-called “skin in the game” that each equity partner puts up to help run the firm and finance its work.

Because of those costs, it's possible—although unlikely—that newly promoted partners will take home less than they did as a senior associate, says James Cotterman, a principal in Altman Weil in Orlando who advises firms on compensation and capital structure.