You may check CBP web site for detail.
j*d+WZm8-g $-s8tc( http://www.cbp.gov ;3%Y@FS@ MIN}5kc< The following is mentioned in U.S. Customs and Border Protection Declaration Form
O:imX>|u i8%@4U/ J Money And Other Monetary
wbg?IvY[ Instruments
K1&t>2=% You may bring into or take out of the country, including
31QDN0o!~ by mail, as much money as you wish. However, if
[lu+"V,<LJ it is more than $10,000, you will need to report it to
X}ihYM3y/ CBP. Ask the CBP officer for the Currency Reporting
YHxQb$v) Form (FinCen 105). The penalties for non-compliance
qt4%=E;[ can be severe.
,4;'s “Money” means monetary instruments and includes U.S.
Mq#Hi9SKY or foreign coins currently in circulation, currency, travelers’
*<}R=X. checks in any form, money orders, and negotiable
%:sP #BQM instruments or investment securities in bearer form.