# Post-grant review (PGR)

A USPTO proceeding to challenge a recently granted patent, within nine months of grant, on almost any ground of invalidity — including eligibility and written description. It is broader than inter partes review, which is narrower and becomes available later.

**Full entry:** https://patentbrief.org/glossary/post-grant-review

**All patent terms:** https://patentbrief.org/glossary

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_Source: PatentBrief — https://patentbrief.org. A plain-English glossary of US patent terms._