Mrs Dierman, a senior career diplomat, is currently Deputy Assistant Secretary in the Bureau of Human Resources at the Department of State.
Her other overseas posts have also focused on public diplomacy programming and included Pretoria, Berne and Berlin.
She will arrive in Bermuda in mid-June to replace Mary Ellen Koenig, who leaves on April 30.
Mrs Dierman has served in Kabul, Baghdad, Bridgetown, Canberra and Geneva.
Also, it is the only country in the world that requires its own individual US citizens and residents to pay US taxes not just on their US income but on their world-wide income, another major concern to US corporations.
US corporations that use Bermuda as a tax shelter include many dozens in the AIG group, GE, hundreds in the Chevron group and thousands more.
The USA requires all Bermudians, US citizens working in Bermuda or elsewhere abroad and others who have any stocks and shares or real estate or any financial interest in the USA to file US Tax returns, the only country in the world to to so. Written in part to celebrate Bermuda's 400th anniversary in 2009.