In their scramble to shield their wealth from higher taxes, America's richest individuals are considering relocating to tax-friendlier states and, in some cases, countries.

In January, international financial advisory firm deVere Group saw a 48% month-on-month increase in the number of high-net-worth individuals—those with $1 million or more in assets—inquiring about permanently relocating outside the United States.

"When high-net-worth individuals are taxed to perceived excessive levels, they simply move to lower jurisdictions because they have the resources to do so," Nigel Green, CEO of the deVere Group, an international financial advisory firm, says in a statement.

Among some of the high-profile individuals who abandoned the U.S. for lower-tax countries are Eduardo Saverin, the billionaire co-founder of Facebook who recently moved to Singapore, and socialite and songwriter Denise Rich, who became an Austrian citizen and moved to London.

"It's a global trend demonstrated by Gérard Depardieu giving up his French passport in favor of Russian nationality, and France's richest man, luxury goods magnate Bernard Arnault, having transferred his multi-billion euro fortune to Belgium in response to Hollande's threat of a millionaire's tax," Green says.