MPEP 2143.03
All Claim Limitations Must Be Considered

Ninth Edition of the MPEP, Revision 07.2022, Last Revised in February 2023

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2143.03    All Claim Limitations Must Be Considered [R-07.2022]

"All words in a claim must be considered in judging the patentability of that claim against the prior art." In re Wilson, 424 F.2d 1382, 1385, 165 USPQ 494, 496 (CCPA 1970).

Examiners must consider all claim limitations when determining patentability of an invention over the prior art. In re Gulack, 703 F.2d 1381, 1385, 217 USPQ 401, 403-04 (Fed. Cir. 1983). The subject matter of a properly construed claim is defined by the terms that limit the scope of the claim when given their broadest reasonable interpretation. See MPEP § 2111 et seq. It is this subject matter that must be examined. The determination of whether particular language is a limitation in a claim depends on the specific facts of the case. See, e.g., Griffin v. Bertina, 285 F.3d 1029, 1034, 62 USPQ2d 1431 (Fed. Cir. 2002).

As a general matter, the grammar and ordinary meaning of terms as understood by one having ordinary skill in the art used in a claim will dictate whether, and to what extent, the language limits the claim scope. Language that suggests or makes a feature or step optional but does not require that feature or step does not limit the scope of a claim under the broadest reasonable claim interpretation. In addition, when a claim requires selection of an element from a list of alternatives, the prior art teaches the element if one of the alternatives is taught by the prior art. See, e.g., Fresenius USA, Inc. v. Baxter Int’l, Inc., 582 F.3d 1288, 1298, 92 USPQ2d 1163, 1171 (Fed. Cir. 2009).

The following types of claim language may raise a question as to its limiting effect (this list is not exhaustive):

If an independent claim is nonobvious under 35 U.S.C. 103, then any claim depending therefrom is nonobvious. In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988). However, this conclusion of the Fine court may not apply if a claim is not properly dependent. See MPEP § 608.01(n) for a discussion of dependent claims.


A claim limitation which is considered indefinite cannot be disregarded. If a claim is subject to more than one interpretation, at least one of which would render the claim unpatentable over the prior art, the examiner should reject the claim as indefinite under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph (see MPEP § 2175) and should reject the claim over the prior art based on the interpretation of the claim that renders the prior art applicable. Ex parte Ionescu, 222 USPQ 537 (Bd. Pat. App. & Inter. 1984) (Claims on appeal were rejected on indefiniteness grounds only; the rejection was reversed and the case remanded to the examiner for consideration of pertinent prior art.). Making both rejections, when appropriate, avoids piecemeal appellate review. See Ionescu, 222 USPQ at 540 n.9 (citing CCPA and Federal Circuit cases.). See also In re Wilson, 424 F.2d 1382, 165 USPQ 494 (CCPA 1970) (The Board erred because it ignored claim language that it considered to be indefinite, and reached a conclusion that the claim would have been obvious based only on the rest of the claim.). However, an examiner should not simply speculate about the meaning of the claim language and then enter an obviousness rejection in view of that speculative interpretation. In re Steele, 305 F.2d 859,134 USPQ 292 (CCPA 1962) (The "considerable speculation" by the examiner and the Board as to the scope of the claims did not provide a proper basis for an obviousness rejection.). A claim should not be rejected over prior art just because it is indefinite. Ionescu, 222 USPQ at 540 (citing Steele). Although a claim that is indefinite because it is susceptible to more than one interpretation may be rejected over prior art, an examiner should not base a prior art rejection on a claim interpretation that is not reasonable; see MPEP § 2111 regarding proper claim interpretation.


When evaluating claims for obviousness under 35 U.S.C. 103, all the limitations of the claims must be considered and given weight, including limitations which do not find support in the specification as originally filed (i.e., new matter). Ex parte Grasselli, 231 USPQ 393 (Bd. App. 1983) aff’d mem. 738 F.2d 453 (Fed. Cir. 1984) (Claim to a catalyst expressly excluded the presence of sulfur, halogen, uranium, and a combination of vanadium and phosphorous. Although the negative limitations excluding these elements did not appear in the specification as filed, it was error to disregard these limitations when determining whether the claimed invention would have been obvious in view of the prior art.).