How to Check If a US Patent Is Still Active

Before you rely on — or design around — a US patent, you need to know whether it is still in force. A patent can be legally dead for three reasons: it reached natural expiry, it lapsed because a maintenance fee went unpaid, or it was invalidated. Here is how to check.

Step 1 — Look up the patent in USPTO Patent Center

Search the patent number in the free USPTO Patent Center. The record shows the grant date, the assignee, and the maintenance fee payment history — including whether each 3.5, 7.5 and 11.5-year fee has been paid.

Step 2 — Check the maintenance fee status

If a required maintenance fee is unpaid and past its grace period, the patent has lapsed and the technology is in the public domain. The USPTO's Patent Maintenance Fees Storage System (bulk data) records every fee event and is the authoritative source PatentLapse monitors.

Step 3 — Calculate natural expiry

A US utility patent generally expires 20 years from its earliest non-provisional filing date, subject to any Patent Term Adjustment or Extension. Even a fully-maintained patent is dead after that date.

Step 4 — Watch for reinstatement

A recently lapsed patent is not always safe to use: the holder may petition to revive it if the non-payment was unintentional. Confirm there is no pending petition before acting on a lapse.

Checking a single patent by hand is straightforward; monitoring a portfolio of competitor patents for status changes is not. PatentLapse watches USPTO fee events continuously and alerts you within a day of any watched patent entering a fee window or lapsing.

Last updated: 2026-08-30 · Data: USPTO public domain · Not legal advice — consult a patent attorney before acting on this information.