You may check CBP web site for detail.
QnJZr:4b uH(f$A http://www.cbp.gov lR(+tj)9uO 07[_.i.l The following is mentioned in U.S. Customs and Border Protection Declaration Form
g4l
!xT TTKs3iTXz Money And Other Monetary
#Jw1IcuH Instruments
sIxTG y. You may bring into or take out of the country, including
=W"F[fD by mail, as much money as you wish. However, if
C<P%CG&; it is more than $10,000, you will need to report it to
ihfiK|a CBP. Ask the CBP officer for the Currency Reporting
q,+yqrt Form (FinCen 105). The penalties for non-compliance
}&[ can be severe.
lMBLIB]i “Money” means monetary instruments and includes U.S.
43@{JK9G or foreign coins currently in circulation, currency, travelers’
fP.
6HF_p_ checks in any form, money orders, and negotiable
2'W<h)m)z instruments or investment securities in bearer form.