Question: Can a party plead the 5th Amendment in a civil case and not answer certain questions?
Answer: Yes, but that party does so at their peril. See below
It is a bedrock principle of our criminal justice system that no person … shall be compelled in any criminal case to be a witness against themself. The 5th Amendment, not only protects the individual against being involuntarily called as a witness against themself in a criminal prosecution, but also privileges them not to answer official questions put to them in any other proceeding, where the answers might incriminate them in future criminal proceedings. A civil defendant who chooses to avail themself of this protection, however, does so at their peril: the 5th Amendment does not forbid adverse inferences against parties to civil actions when they refuse to testify in response to evidence offered against them.
But “even where privileges as important as the Fifth Amendment privilege against self-incrimination are implicated, courts in civil proceedings have taken steps to ensure that the litigation proceeds in a manner consistent with the interests of justice.” One such step is the exercise of the court’s inherent power to stay its proceedings. Although it is under no constitutional obligation to do so, the court has discretion to impose a stay when the “interests of justice” so require. Courts also frequently consider the status of the parallel criminal proceeding in determining whether a stay is warranted.