You may check CBP web site for detail.
j /dE6d Z F yX@#B9 http://www.cbp.gov ElR&scXi__ ^x"c 0R^ The following is mentioned in U.S. Customs and Border Protection Declaration Form
#C;zS9(]B W;oU +z^t$ Money And Other Monetary
p/WH#4Xdr Instruments
dFP-(dX# You may bring into or take out of the country, including
Jv^cOc by mail, as much money as you wish. However, if
*tfDXQ^mN it is more than $10,000, you will need to report it to
9#T%bB"J CBP. Ask the CBP officer for the Currency Reporting
T~~[a|bLa Form (FinCen 105). The penalties for non-compliance
?~JxO/K can be severe.
1;:t~Y “Money” means monetary instruments and includes U.S.
,C,e/>+My or foreign coins currently in circulation, currency, travelers’
T19rbL_ checks in any form, money orders, and negotiable
`I vw`} L instruments or investment securities in bearer form.