Yes, several organizations work specifically with foreign nationals in Bureau of Prisons custody and their families, though the type of help available varies depending on what the situation requires.
For consular assistance, the most immediate resource is the embassy or consulate of the inmate's home country. Under the Vienna Convention on Consular Relations, foreign nationals who are arrested or imprisoned in the United States have the right to have their consulate notified and to receive consular visits. Many consulates have staff specifically assigned to assist their nationals in US custody, which can include help with communication, legal referrals, and in some cases financial assistance for families.
For legal support, the National Immigrant Justice Center and the American Immigration Council both work on issues affecting non-citizen detainees and inmates, including matters related to deportation orders that often run alongside criminal sentences for foreign nationals. Understanding how a federal sentence interacts with immigration consequences is critically important and often requires specialized legal help that general criminal defense attorneys are not equipped to provide.
For family support, the Vera Institute of Justice and the Families Against Mandatory Minimums organization both advocate for incarcerated people and their families, including those who are foreign nationals. They can sometimes connect families with local resources depending on where the family is located.
The specific kind of help that would be most useful, whether legal, financial, communication support, or something else, determines which of these organizations is the right starting point. If you can share more about what your situation requires, a more targeted direction is possible.