When a case has been removed to federal court before an answer has been filed when is the answer to the Complaint due?

Federal Rules of Civil Procedure Rule 81(c)(2) appears to apply to this question. That rule subsection, entitled APPLICABILITY OF THE RULES IN GENERAL; REMOVED ACTIONS provides the following:

(c) Removed Actions.

(1) Applicability. These rules apply to a civil action after it is removed from a state court.

(2) Further Pleading. After removal, repleading is unnecessary unless the court orders it. A defendant who did not answer before removal must answer or present other defenses or objections under these rules within the longest of these periods:

(A) 21 days after receiving-through service or otherwise-a copy of the initial pleading stating the claim for relief;

(B) 21 days after being served with the summons for an initial pleading on file at the time of service; or

(C) 7 days after the notice of removal is filed.

You should consult an attorney in your jurisdiction to verify this information's applicability to your case, and to see what local federal court rules, if any, may apply to your situation.