Lily Adams, a veteran of Vice President Kamala Harris’ presidential bid, is joining the Treasury Department to help promote the $1.9 trillion American Rescue Plan and the administration’s broader plans to combat income inequality.

Why it matters: Touting Biden’s stimulus package will be a government-wide effort, with a coordinated communications strategy. Treasury is taking the lead on implementing it, and Adams will play a key role.

• Adams will help calibrate that campaign, underscoring the close linkage between the White House and Treasury.
• Treasury Secretary Janet Yellen has been receiving strategic communications help from Natalie Wyeth Earnest, who served as assistant secretary for public affairs for President Obama. She plans to leave this spring.
• As principal deputy secretary for public affairs, Adams will join a team led by Calvin Mitchell, the current assistant secretary. Alexandra LaManna serves as the department's spokesperson.

The big picture: Yellen is slowly filling out her staff, with Wally Adeyemo, President Biden’s nominee for deputy Treasury secretary, expected to be confirmed by the Senate this month.

• Last week, Biden announced Nellie Liang, a former economist at the Federal Reserve, as his pick to serve as undersecretary for domestic finance.
• Ben Harris, a trusted Biden confidant who helped craft the COVID-19 relief package and the "Build Back Better" program during the campaign, has been nominated to be assistant secretary for economic policy.
• He will be another key link between Treasury and the White House.

Go deeper: Biden still has not named an undersecretary for international affairs, the department's top diplomat, or undersecretary for terrorism and financial intelligence, which would play a key role in any potential nuclear deal with Iran.

• Nancy Lee, Heidi Crebo-Rediker and Marisa Lago are among the candidates being considered for the international affairs job, according to Bloomberg.
• David Lipton, who had the international affairs job under President Clinton and held the No. 2 position at the International Monetary Fund, has returned to Treasury as a senior counselor.

Between the lines: Biden hasn’t announced a big-name Wall Street figure to join Treasury, a sign he's reluctant to antagonize Sen. Elizabeth Warren (D-Mass.) or other progressives in his party.

• President Obama tested his luck with Antonio Weiss, an investment banker at Lazar, for domestic finance, but withdrew his name after Warren objected.
• But Obama then installed Weiss as a counselor, giving then-Treasury Secretary Jack Lew an in-house expert on the mechanics of financial markets. A similar end-run is a possibility in the current 50-50 Senate.

The bottom line: There’s a tunnel connecting the Treasury Department to the East Wing of the White House, making Treasury the only (known) department with direct — and discreet — access to the Oval Office.

• When the secretaries of Defense or State arrive for National Security Council meetings in the Situation Room, their motorcade parks on West Executive Avenue, where TV cameras can capture their arrival.
• But the Treasury secretary, along with any CEOs in tow, can slip into the White House without the public knowing.