35 U.S.C. § 4
Section 4 · Restrictions on officers and employees as to interest in patents
Amended 2 times on record
Applied in 105 court decisions — leading case Reeves Brothers, Inc. v. US Laminating Corp. (1968)
Most recently applied in United States v. Marilyn Mosby (July 2025)
Cases citing this section usually also cite 12 U.S.C. § 4 · 13 U.S.C. § 4 · 14 U.S.C. § 4
How often courts cite this section
Court decisions citing this, by year.Markers show enactment, consequential amendments, and circuit splits over this section — watch for a citation surge after a change or a disagreement. The dip in the last several years is a data-coverage gap, not a real trend — our corpus holds fewer opinions from the most recent years, so recent citations are undercounted.
Officers and employees of the Patent and Trademark Office shall be incapable, during the period of their appointments and for one year thereafter, of applying for a patent and of acquiring, directly or indirectly, except by inheritance or bequest, any patent or any right or interest in any patent, issued or to be issued by the Office. In patents applied for thereafter they shall not be entitled to any priority date earlier than one year after the termination of their appointment.
Editorial notes U.S. Code · Office of the Law Revision Counsel
Historical and Revision Notes
Based on Title 35, U.S.C., 1946 ed., §4 (R.S. 480).
The language is revised and inability to apply for a patent, included in the original language, is made explicit.
The period of disability is increased to include one year after leaving the Office.
The further restriction, that no priority date earlier than one year after leaving the Office can be claimed, is added.
The one year period is made inapplicable to applications which may be pending when the revised title goes into effect by section 4(g) of the bill.
Amendments
1975—Pub. L. 93–596 substituted “Patent and Trademark Office” for “Patent Office”.
Effective Date of 1975 Amendment
Amendment by Pub. L. 93–596 effective Jan. 2, 1975, see section 4 of Pub. L. 93–596, set out as a note under section 1111 of Title 15, Commerce and Trade.