You may check CBP web site for detail.
CD)JCv {br6* http://www.cbp.gov {\n?IGP?wd ?rQIUP{D7 The following is mentioned in U.S. Customs and Border Protection Declaration Form
R(#ZaFuo[ P:m6:F@hO Money And Other Monetary
f+4j ^y} Instruments
pUeok+k_ You may bring into or take out of the country, including
R rp-SR?O by mail, as much money as you wish. However, if
uX+ YH it is more than $10,000, you will need to report it to
XM:
\N$tg CBP. Ask the CBP officer for the Currency Reporting
@gjA8mL Form (FinCen 105). The penalties for non-compliance
v
=E(U4v9e can be severe.
@"/:Omh “Money” means monetary instruments and includes U.S.
oN=>U"<\1 or foreign coins currently in circulation, currency, travelers’
c{})Z= checks in any form, money orders, and negotiable
Mo[
yRRS# instruments or investment securities in bearer form.