You may check CBP web site for detail.
J Eo;Fx] CLe{9-o http://www.cbp.gov B(vCi^ On~KTt3Mp The following is mentioned in U.S. Customs and Border Protection Declaration Form
`-P1Y [7~AWZU3 Money And Other Monetary
)8rF'pxI Instruments
,!alNNY You may bring into or take out of the country, including
>5Lp; by mail, as much money as you wish. However, if
3 yb]d5:U it is more than $10,000, you will need to report it to
zv0sz]) CBP. Ask the CBP officer for the Currency Reporting
~x/ka43 Form (FinCen 105). The penalties for non-compliance
]+m2pEO can be severe.
[7HBn “Money” means monetary instruments and includes U.S.
=M4:nt or foreign coins currently in circulation, currency, travelers’
>i >|] checks in any form, money orders, and negotiable
~Ey+ instruments or investment securities in bearer form.