You may check CBP web site for detail.
9IKFrCO9, aZYa<28?L% http://www.cbp.gov 4425,AR O4kBNUI/ The following is mentioned in U.S. Customs and Border Protection Declaration Form
X$zlR)Re )POuH*j Money And Other Monetary
pC2r{- Instruments
&Z_W*D You may bring into or take out of the country, including
P+sxlf:0 by mail, as much money as you wish. However, if
;(Q4x"?I it is more than $10,000, you will need to report it to
$up.<qzj CBP. Ask the CBP officer for the Currency Reporting
zQ$*!1FmN Form (FinCen 105). The penalties for non-compliance
zA&lJD$0 can be severe.
8VJUaL@ “Money” means monetary instruments and includes U.S.
oXgKuR or foreign coins currently in circulation, currency, travelers’
A+T!DnVof checks in any form, money orders, and negotiable
e`#c[lbAAM instruments or investment securities in bearer form.