MPEP § 2164.08(b) — Inoperative Subject Matter (Annotated Rules)

§2164.08(b) Inoperative Subject Matter

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 2164.08(b), including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Inoperative Subject Matter

This section addresses Inoperative Subject Matter. Contains: 1 permission and 2 other statements.

Key Rules

Topic

Scope Commensurate with Disclosure

3 rules
MPEP GuidancePermittedAlways
[mpep-2164-08-b-67904d8cb06ee619c7c00743]
Scope Not Enabled by Undue Experimentation
Note:
Claims must not extend beyond the disclosed embodiments that can be determined to be operable without undue experimentation.

Although, typically, inoperative embodiments are excluded by language in a claim (e.g., preamble), the scope of the claim may still not be enabled where undue experimentation is involved in determining those embodiments that are operable. A disclosure of a large number of operable embodiments and the identification of a single inoperative embodiment did not render a claim broader than the enabled scope because undue experimentation was not involved in determining those embodiments that were operable. In re Angstadt, 537 F.2d 498, 502-503, 190 USPQ 214, 218 (CCPA 1976). However, claims reading on significant numbers of inoperative embodiments would render claims nonenabled when the specification does not clearly identify the operative embodiments and undue experimentation is involved in determining those that are operative. Atlas Powder Co. v. E.I. duPont de Nemours & Co., 750 F.2d 1569, 1577, 224 USPQ 409, 414 (Fed. Cir. 1984); In re Cook, 439 F.2d 730, 735, 169 USPQ 298, 302 (CCPA 1971).

Jump to MPEP SourceScope Commensurate with DisclosureUndue ExperimentationOptional Claim Content
MPEP GuidanceInformativeAlways
[mpep-2164-08-b-bce86673136e71d7a5f3ddbc]
Claims Must Not Exceed Enabled Embodiments
Note:
Claims must not include embodiments that are inoperative unless the specification clearly identifies them and undue experimentation is required to determine operability.

Although, typically, inoperative embodiments are excluded by language in a claim (e.g., preamble), the scope of the claim may still not be enabled where undue experimentation is involved in determining those embodiments that are operable. A disclosure of a large number of operable embodiments and the identification of a single inoperative embodiment did not render a claim broader than the enabled scope because undue experimentation was not involved in determining those embodiments that were operable. In re Angstadt, 537 F.2d 498, 502-503, 190 USPQ 214, 218 (CCPA 1976). However, claims reading on significant numbers of inoperative embodiments would render claims nonenabled when the specification does not clearly identify the operative embodiments and undue experimentation is involved in determining those that are operative. Atlas Powder Co. v. E.I. duPont de Nemours & Co., 750 F.2d 1569, 1577, 224 USPQ 409, 414 (Fed. Cir. 1984); In re Cook, 439 F.2d 730, 735, 169 USPQ 298, 302 (CCPA 1971).

Jump to MPEP SourceScope Commensurate with DisclosureUndue ExperimentationEnablement Support for Claims
MPEP GuidanceInformativeAlways
[mpep-2164-08-b-446b831daeaf86fa6deaa52b]
Claims Must Not Read on Significant Inoperative Embodiments
Note:
Claims must not cover significant numbers of inoperative embodiments without clear identification and enablement support.

Although, typically, inoperative embodiments are excluded by language in a claim (e.g., preamble), the scope of the claim may still not be enabled where undue experimentation is involved in determining those embodiments that are operable. A disclosure of a large number of operable embodiments and the identification of a single inoperative embodiment did not render a claim broader than the enabled scope because undue experimentation was not involved in determining those embodiments that were operable. In re Angstadt, 537 F.2d 498, 502-503, 190 USPQ 214, 218 (CCPA 1976). However, claims reading on significant numbers of inoperative embodiments would render claims nonenabled when the specification does not clearly identify the operative embodiments and undue experimentation is involved in determining those that are operative. Atlas Powder Co. v. E.I. duPont de Nemours & Co., 750 F.2d 1569, 1577, 224 USPQ 409, 414 (Fed. Cir. 1984); In re Cook, 439 F.2d 730, 735, 169 USPQ 298, 302 (CCPA 1971).

Jump to MPEP SourceScope Commensurate with DisclosureUndue ExperimentationOptional Claim Content

Citations

Primary topicCitation
Scope Commensurate with DisclosureIn re Cook, 439 F.2d 730, 735, 169 USPQ 298, 302 (CCPA 1971)

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31