Linda Mangano's request for bail has been denied by the United States Court of Appeals for the Second Circuit.
She will now have to surrender on Friday to begin serving her 15-month jail sentence.
The Manganos were both convicted of accepting bribes.
The wife of former Nassau County Executive Ed Mangano was found guilty of obstruction of justice and lying to the FBI.
She had a "no-show job" through a businessman through which she collected $450,000.