35 U.S.C. · Part II · Chapter 11, Application for patent
35 U.S.C. 120: Benefit of earlier filing date in the United States
In plain English
Section 120 lets a later US application claim the filing date of an earlier US nonprovisional or PCT application. This is the statutory basis for continuations, divisionals and continuations-in-part. Four conditions apply: the earlier application must disclose the invention as required by section 112(a) (except best mode); the two must share at least one named inventor; the later one must be filed before the earlier one is patented, abandoned or otherwise terminated (copendency); and the later one must contain a specific reference to the earlier one.
Benefit can run through a chain of applications, as long as each link is copending with the one before it. A continuation repeats the parent's disclosure and pursues different claims. A divisional does the same for an invention cut out by a restriction requirement (section 121). A continuation-in-part adds new matter, and only claims fully supported by the parent get the parent's date.
The specific reference must be made within the time the USPTO sets, or the benefit claim is treated as waived. A late claim can be accepted on petition if the delay was unintentional, with a fee.
Annotation by Raj Sutariya, Co-founder, PatentAssist.ai. General information, not legal advice; the statute below governs.
Text of 35 U.S.C. 120
Current text, quoted from the official United States Code.
An application for patent for an invention disclosed in the manner provided by section 112(a) (other than the requirement to disclose the best mode) in an application previously filed in the United States, or as provided by section 363 or 385, which names an inventor or joint inventor in the previously filed application shall have the same effect, as to such invention, as though filed on the date of the prior application, if filed before the patenting or abandonment of or termination of proceedings on the first application or on an application similarly entitled to the benefit of the filing date of the first application and if it contains or is amended to contain a specific reference to the earlier filed application. No application shall be entitled to the benefit of an earlier filed application under this section unless an amendment containing the specific reference to the earlier filed application is submitted at such time during the pendency of the application as required by the Director. The Director may consider the failure to submit such an amendment within that time period as a waiver of any benefit under this section. The Director may establish procedures, including the requirement for payment of the fee specified in section 41(a)(7), to accept an unintentionally delayed submission of an amendment under this section.
Practical notes
For applications filed under section 111(a), the benefit claim is due by the later of 4 months from the filing of the later application or 16 months from the filing of the earlier one, and it must be in an application data sheet (37 CFR 1.78(d)). Many practitioners put it in the first sentence of the specification as well, but the application data sheet is what counts.
Copendency means the child must be filed before the parent issues, not before the issue fee is paid. There is a window of several weeks between the two, and missing it ends the family. If you want a continuation, file it before the issue date on the issue notification.
The 20-year term of every application in the chain runs from the earliest nonprovisional parent it claims under section 120 (section 154(a)(2)). Continuations therefore extend prosecution, not exclusivity, and they often draw obviousness-type double patenting rejections that are resolved by a terminal disclaimer.
Related rules and guidance
- 37 CFR
- § 1.53, § 1.76, § 1.78
- MPEP
- 201, 211
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All annotated sections of 35 U.S.C.
Statute text from the United States Code published by the Office of the Law Revision Counsel of the U.S. House of Representatives (uscode.house.gov). Text contains those laws in effect through Public Law 119-124 (October 15, 2026). Editorial notes and footnotes are omitted. The annotations are general information, not legal advice; check the official text and a registered patent practitioner before relying on them.