Emily M. Lam

Even among lawyers reticent about clients with sensitive matters, Lam is tight-lipped about the high-profile companies and high-net-worth individuals she represents. "The reality is that the vast majority of what I do is confidential," she said. "My practice is not transparent."

She declined to comment on the recent Panama Papers tax-avoidance revelations, and she had nothing to say about corporate tax inversion strategies except to note that she does not do transactions. "My practice has a counseling aspect and an adversarial part," she said. "I spend a lot of time interfacing with the IRS and strategizing with clients on how best to proceed."

Her current docket is impressive, if opaque. Lam leads Skadden's representation of a large technology company on various federal and state tax matters, including income tax, employment tax and mobility issues. She is the lead lawyer handling the charitable aspects of Skadden's advice to an individual taxpayer regarding the establishment of a private foundation, gifts to various charities and structuring other philanthropic ventures. She leads Skadden's representation of a foreign government on a matter before IRS Appeals related to the government's investments in the U.S. She's the lead lawyer representing a global hotel and resort company on its domestic tax issues before IRS Appeals, including an approximately $1 billion tax accounting issue.

Lam, previously an attorney at Skadden, rejoined the firm in 2010 after working as an attorney advisor in the Office of Tax Policy at the U.S. Department of the Treasury. There, she advised the Internal Revenue Service on administration, consulted with congressional staff regarding legislation and dealt with other government agencies on tax policy matters. So she knows her way around the bureaucracy. "I deal with former colleagues in D.C. and at Treasury, and in the way of revolving doors, I have e-colleagues from Skadden who are now at the IRS. There's a lot of relationship building. I absolutely make cold calls, but because I've been on the government side, I understand [tax authorities'] mind set, their triggers, what matters to them."

? John Roemer