Hello
My wife has inherited a sum of money in Bolivia ,she wants to transfer the amount from there to the US where she is a citizen.How does she go about this paying the least amount in tax?
Thanks

There is no tax on that money. In America gifts and bequests are not considered income.

Nevertheless, if it is $100,000 or over an informational form is required to be submitted.
See: http://www.irs.gov/pub/irs-pdf/f3520.pdf
http://www.irs.gov/pub/irs-pdf/i3520.pdf

If the amount transferred exceed $100,000, file form 3520.
If you or your wife have foreign account, then you may have to file Form TD F 90-22.1.