---
type: "LegalText"
title: "43 U.S.C. § 2506"
description: "Limitations of suits to annul patents"
jurisdiction: "us"
corpus: "united_states_code"
kind: "code_section"
title_number: 43
title_name: "PUBLIC LANDS"
chapter_number: "43"
chapter_name: "SUSPENDED ENTRIES AND CLAIMS; PATENTS"
section: "2506"
citation: "43 U.S.C. § 2506"
status: "current"
release_point: "119-100"
release_date: "2026-06-26"
source: "official"
source_url: "https://uscode.house.gov/download/releasepoints/us/pl/119/100/xml_usc43@119-100.zip"
source_identifier: "/us/usc/t43/s2506"
source_file: "data/legal/raw/us/code/title-43/usc43.xml"
source_hash: "ce683ee69b60dbc732137210e173a18941774b4caf561279e7e9b88bb923d877"
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text_hash: "4ca2c0728abe20623707119b917c45e6ff5d2ba8c78c84a9dea686e5a4e74ca8"
retrieved_at: "2026-07-04"
confidence: "official"
tags: ["legal", "us-code"]
---

# 43 U.S.C. § 2506 - Limitations of suits to annul patents

## Text

Suits by the United States to vacate and annul any patent shall only be brought within six years after the date of the issuance of such patents.

(Mar. 3, 1891, ch. 559, 26 Stat. 1093; Mar. 3, 1891, ch. 561, § 8, 26 Stat. 1099.)

## Notes

Editorial Notes

Codification Section was formerly classified to section 1166 of this title prior to editorial reclassification and renumbering as this section.