A patent infringement suit is a federal civil action. Under 35 U.S.C. 281, a patentee may bring a civil action for infringement. Service of the summons and complaint usually starts the response clock; a timely waiver changes that deadline. This page is the short sequence after papers land. For the deep checklist on venue, willfulness, insurance, customers, costs, and ITC naming, see the longer sued FAQ linked in Sources below.
What is the first deadline that matters?
The summons and Federal Rule of Civil Procedure 12 usually control when your answer or Rule 12 motion is due. Many defendants have 21 days after being served with the summons and complaint to serve a responsive pleading under Rule 12(a)(1)(A), or longer after a timely waiver of service under Rule 4(d). Confirm the date on the summons, any waiver papers, and local standing orders. Missing it can lead toward default under Rule 55. Do not assume a "friendly" extension exists until it is in writing and, when required, approved by the court.
What happens in the first two weeks?
Counsel reviews venue, personal jurisdiction, the patents, and how clearly the complaint ties claims to products. You send a hold so email, code, and product files are preserved. You notify insurers and check supplier indemnity. You decide whether to answer or move to dismiss. You do not call the plaintiff's lawyer for an informal product tour without your counsel on the line. You also start a quiet map of damages exposure, including whether the complaint alleges willfulness under 35 U.S.C. 284 and whether marking or actual notice under 35 U.S.C. 287 may limit the back-damages window.
What does the court do after the pleadings?
The parties usually hold a Rule 26(f) conference, and the judge issues a scheduling order under Rule 16. The order sets deadlines for discovery and motions and may address contentions, claim construction, experts, and trial. Local patent rules, judge-specific procedures, and case orders can require early infringement and invalidity contentions. Check the rules and orders governing your case rather than assuming a uniform schedule across districts.
When do claim construction and discovery hit?
Claim construction (often called a Markman process) decides what the patent claims mean. Discovery can begin before claim construction is resolved and presses for technical documents, sales data, source code under protective order, and depositions. Experts arrive later for infringement, validity, and damages. Many cases settle under that pressure before trial. Budget spikes often cluster around contentions and Markman, expert reports and summary judgment, and trial prep; see the cost FAQ for planning ranges.
What parallel tracks should I watch?
The patent owner may also file an ITC section 337 complaint for import-related relief. On the defense side, you may evaluate IPR, PGR, or reexamination at the Patent Office, subject to clocks such as 35 U.S.C. 315(b) for IPR after service of a complaint. Fintiv-style discretionary denial can affect IPR institution when the district case is moving fast. If you are also named in an ITC investigation, 28 U.S.C. 1659 can provide a mandatory district stay of overlapping claims when the request is timely. See the dual-track and Fintiv breakouts for more.
How is this page different from the longer sued FAQ?
The longer FAQ (You've Been Sued for Patent Infringement) answers many detailed questions about service, venue, willfulness, insurance, customers, costs, and ITC naming. Use that page when you need the full checklist. Use this page when you need the sequence of what typically happens next after papers land. Read the two guides together for both an overview and a detailed checklist.
What should I watch next?
Watch your Rule 12 date, the scheduling order, any ITC receipt notice, and the one-year IPR clock if Patent Office challenges are on the table. Also watch whether the complaint pleads willfulness based on a pre-suit letter. Related reading: the longer sued FAQ, the notice-letter FAQ, willfulness, patent marking, Fintiv, dual-track ITC, and the cost FAQ.