Rising to the partnership ranks at an Am Law 200 firm has traditionally required a range of skills that includes a tireless work ethic, a sharp legal mind, and, often, the potential to bring in new business. One thing that seems increasingly unnecessary for those intent on making partner—unwavering loyalty to whichever firm hires them out of law school.

An Am Law Daily analysis of new partner classes at 50 Am Law 200 firms shows that nearly 59 percent of the 499 associates and counsel promoted at those firms began their career elsewhere. Some logged time in government jobs. Many followed partners making lateral moves. Still others traded positions at firms where the odds of rising were slim to those that offered greater opportunities.

Consider Lezlie Madden, a onetime Cravath, Swaine & Moore associate with two clerkships on her resume who made partner this year at Cozen O'Connor in Philadelphia. When Madden left Cravath in 2008 for her second clerkship, with the U.S. Court of Appeals for the Third Circuit, she fully expected to return to New York and Cravath, where she'd spent the summer between her second and third years at Fordham University School of Law.

"Then life got in the way," says Madden, who, like others interviewed for this story, spoke to The Am Law Daily earlier this year. Her husband, also a lawyer, decided he preferred Philadelphia, which also happens to be Madden's hometown. The couple bought a house there, and Madden's job search led her to Cozen. In March, following several rounds of intensive interviews and evaluations, Madden became one of 20 lawyers elevated to what Cozen calls members of the firm (Madden and 16 others were laterals).

While she doesn't downplay how much work it took to get where she is today, Madden says the experience of moving up the law firm ladder wasn't as grueling as she once imagined: "I have found it a much more humane process than I had feared it would be from the nightmares of law students everywhere."

In an environment where making partner remains the exception, rather than the norm, not everyone shares Madden's sentiment. In comment after comment submitted in response to this year's American Lawyer Midlevel Associates Survey—the complete results of which will be published in the magazine's September issue—junior lawyers bemoaned the lack of a visible career path in the firms where they worked. "The associates here seem to have given up on partnership," wrote one Am Law 100 associate. "Be open about the fact 90 percent of us will not make partner," wrote another.

Joi Bourgeois, a legal consultant who works with associates on career development, understands the frustration. "I see tons of smart people who don’t make partner," Bourgeois says. "Either they're not politically well-placed, or it's those who don’t have the drive or the understanding that really more than ever, it's about adding to the business."

Brad Rostolsky, who made partner at Reed Smith in Philadelphia this year, says he realized early on that he needed to make himself an invaluable part of a firm's business plan if he wanted to rise. Before entering Duquesne University School of Law, Rostolsky earned a master's degree in public health so that he would have an edge as a health care lawyer. After graduating from law school in 2002, he joined Post and Schell in Lancaster, Pennsylvania, and began taking on medical malpractice defense cases. That led to a position as an associate in Cozen's transactional and regulatory health care practice. After receiving a recruiter call, he joined Reed Smith, where he specializes in health care privacy laws, in 2006.

"Ultimately for a long time you’re doing work for clients, but your day-to-day clients as an associate are the partners," Rostolsky says. "It's about developing those relationships and expertise in certain areas so people think to go to you."

Bourgeois says junior lawyers hoping to make partner need to follow a plan, which in many cases will involve making a move to a firm they perceive as offering a better chance at success. "If people are moving," she says. "it’s because they need a new platform, somewhere that's better suited, or where they can build more relationships."

Of the 50 firms that reported the breakdown of homegrown lawyers versus lateral hires in their new partner classes, just three promoted exclusively lawyers who began their careers at the firm: Debevoise & Plimpton (three new partners, including one who took a clerkship straight out of law school), Hughes Hubbard & Reed (three new partners), and Skadden, Arps, Slate, Meagher & Flom (eight new partners, including one who joined the firm following a clerkship). At 36 firms, at least half the new partner class was composed of lateral hires. At six others, laterals hired accounted for at least 80 percent of new partner classes. Of those, only Steptoe & Johnson, which elevated four lawyers this year, had a partner class composed entirely of those who began their careers elsewhere.

Across 120 firms that have announced 2013 promotions, 1,238 lawyers received a promotion to partner, an average of 10 per firm. In the majority, the announcements don't specify whether the new partners are being elevated to equity or nonequity status. Of those promotions, 34 percent were women, a rise from last year's average of 32 percent. (See " Women Partner Watch" for a firm-by-firm breakdown.)

Reed Smith partner and litigation department global chair Alexander "Sandy" Thomas, who is involved in the firm's promotion process, says the mobility of associates seeking out partner roles has added a few complications to the system.

"There's an extra burden on the partnership itself to understand a lateral associate’s capabilities, to make careful judgments in what is often a compressed period of time about that associate’s abilities to be promoted," Thomas says. "Instead of having seven, eight, or nine years with someone, we increasingly are faced with having less time than that."

The compressed time frame, Thomas say, is among the reasons Reed Smith is careful not just about who it elevates to partner, but what becomes of them after they make the jump: "We're trying to pay ever more attention, so nobody feels like they made partner and they’re standing on the edge of a cliff."

That does not appear to be a problem for at least some of this year's newly minted partners.

Dismas Locaria, a 2003 University of Maryland School of Law grad who made partner at Venable in Washington, D.C., after spending his entire career at the firm, says his work life has stayed relatively the same since being promoted. "It's not as though on January 1 I was much wiser," he says. "Nothing changed in terms of my capability, but there’s a certain cachet when you're a partner as opposed to an associate. You feel that little bit of credibility and backing."