You may check CBP web site for detail.
OoaY \"d?=uFe http://www.cbp.gov =Ahw%`/&}] n
\ Uh The following is mentioned in U.S. Customs and Border Protection Declaration Form
KO,_6>8]U `C'}e Money And Other Monetary
ct0v$ct>f Instruments
e1P7
.n} You may bring into or take out of the country, including
gpAHC by mail, as much money as you wish. However, if
93D
\R it is more than $10,000, you will need to report it to
xNgt[fLpS CBP. Ask the CBP officer for the Currency Reporting
3qo e^e Form (FinCen 105). The penalties for non-compliance
}1>atgq]w can be severe.
(,LL[&;: “Money” means monetary instruments and includes U.S.
e&3#2_ or foreign coins currently in circulation, currency, travelers’
t!jwY /T checks in any form, money orders, and negotiable
:]c=pH instruments or investment securities in bearer form.