You may check CBP web site for detail.
e,vgD kI; #;2mP6a[ http://www.cbp.gov <c`,fd8 ygm=q^bV]s The following is mentioned in U.S. Customs and Border Protection Declaration Form
">|L< ^CwS'/fdN Money And Other Monetary
'&/Y}] Instruments
W*c^(W You may bring into or take out of the country, including
=w7k@[Bq by mail, as much money as you wish. However, if
Rv*x'w
== it is more than $10,000, you will need to report it to
~O;?;
@ CBP. Ask the CBP officer for the Currency Reporting
$v{sb, Form (FinCen 105). The penalties for non-compliance
=aT8=ihP can be severe.
^-#:T “Money” means monetary instruments and includes U.S.
I
L8&MA% or foreign coins currently in circulation, currency, travelers’
N*w{NB 7L checks in any form, money orders, and negotiable
1iY?t instruments or investment securities in bearer form.