Overcoming an Obviousness Rejection: A Practical Checklist

Summary. Obviousness under 35 U.S.C. § 103 is the single most common and most consequential ground on which patent claims are rejected. This checklist walks you through dismantling a § 103 rejection: confirming claim construction, testing whether the examiner actually made out a prima facie case (differences, a reasoned motivation to combine, and a reasonable expectation of success), and deploying the substantive rebuttals—attacking the motivation, negating the expectation of success, teaching away, non-analogous art, change in principle of operation, and the full set of objective indicia of nonobviousness with the all-important nexus requirement. It explains the KSR rationales and their hidden factual predicates, the role of Rule 1.132 declarations and examiner interviews, and the different burdens before the examiner, the PTAB, and the district court. The goal is to overcome the rejection while keeping claims broad enough to be worth owning.

Obviousness is the highest, most frequently encountered, and most slippery hurdle between an inventor and an enforceable patent. Unlike anticipation, § 103 asks a counterfactual, judgment-laden question—would the claimed invention as a whole have been obvious to a person of ordinary skill in the art (POSITA) before the effective filing date?—and lets the examiner combine references, modify a single reference, or invoke "common sense." Because the inquiry is so open-textured, most prosecution responses are won and lost here. This checklist gives you the moves. For the doctrine in full, pair it with overcoming obviousness rejections: a comprehensive guide to Section 103 analysis and the procedural responding to a patent office action checklist.

Phase 1 — Set the frame

Confirm which regime applies (post-AIA § 103 for effective filing dates on/after March 16, 2013; pre-AIA otherwise)—it changes what qualifies as prior art.
Verify the examiner's claim construction under broadest reasonable interpretation; anchor terms in your specification (Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005)).
Pin down the level of ordinary skill (the POSITA). A higher skill level makes combinations look more obvious; argue for the modest, defensible level the field actually supports (Daiichi Sankyo Co. v. Apotex, Inc., 501 F.3d 1254 (Fed. Cir. 2007)).
Identify the primary reference, the secondary references, and exactly which limitation each is cited to supply.

Phase 2 — Test the prima facie case (the cheapest win)

Confirm the examiner identified all the differences between the claim and the prior art, with a faithful mapping of every limitation.
Confirm the examiner articulated a reason a POSITA would have combined or modified the references (the motivation requirement—the heart of the case).
Confirm the examiner established a reasonable expectation of success (MPEP § 2143.02; In re Kubin, 561 F.3d 1351 (Fed. Cir. 2009)).
If any element is missing, say so directly—the most efficient win costs nothing in claim scope.

Why this matters. The examiner bears the initial burden of a prima facie case (MPEP §§ 2142, 2143); only then does the burden shift to you. Showing the case was never properly made is the first and best line of attack.

Phase 3 — Check the cited KSR rationale against its predicates

Identify which MPEP § 2143 rationale the examiner invoked (e.g., combine known elements for predictable results; simple substitution; obvious to try; design incentive/market force; surviving TSM).
Hold the rationale to its factual predicates—the rationale is a label, not a conclusion.
For "obvious to try," confirm there genuinely was a finite number of identified, predictable solutions, not "throwing darts at a board" (In re Kubin, 561 F.3d at 1359).
For "simple substitution," confirm the substituted element was a known equivalent functioning the same way for a predictable result.
Quote the MPEP's own requirements back to the examiner—reframe the dispute from "is this obvious?" to "has the examiner met the agency's checklist?"

Phase 4 — Attack the motivation to combine

Argue the references are too different to combine (disparate fields, scales, or purposes weigh against motivation—Adidas AG v. Nike, Inc., 963 F.3d 1355 (Fed. Cir. 2020)).
Expose conclusory combinations—"obvious because it yields predictable results," with no explanation of why predictable or what prompts the combination (In re NuVasive, Inc., 842 F.3d 1376 (Fed. Cir. 2016); Arendi S.A.R.L. v. Apple Inc., 832 F.3d 1355 (Fed. Cir. 2016)).
Show the combination would defeat a reference's purpose or render it inoperable (In re Gordon, 733 F.2d 900 (Fed. Cir. 1984)).
Name impermissible hindsight: the only "reason" is the applicant's own disclosure used as a roadmap.

Phase 5 — Negate the reasonable expectation of success

Distinguish motivation from expectation—one can want to combine and still lack any basis to expect success (Intelligent Bio-Systems, Inc. v. Illumina Cambridge Ltd., 821 F.3d 1359 (Fed. Cir. 2016)).
Frame the predictability of the art: in unpredictable arts (chemistry, pharma, biotech), the prima facie case demands a specific motivation and concrete evidence (often data) of expected success (In re Kubin; Eisai Co. v. Dr. Reddy's Laboratories, Ltd., 533 F.3d 1353 (Fed. Cir. 2008)).
Show the art gave no indication which parameters were critical or which option would succeed.

Phase 6 — Deploy the other primary-factor rebuttals

Teaching away: a reference that criticizes, discredits, or warns against the examiner's path (In re Gurley, 27 F.3d 551 (Fed. Cir. 1994)).
Change in principle of operation / unsatisfactory for intended purpose (In re Ratti, 270 F.2d 810 (C.C.P.A. 1959)).
Non-analogous art: the reference is neither from the inventor's field nor reasonably pertinent to the problem.
Build the affirmative Graham record: scope/content of the art, the precise missing element/arrangement, what a POSITA actually knew, and the objective evidence.

Phase 7 — Marshal objective indicia (secondary considerations)

Gather evidence in the recognized categories: commercial success, long-felt but unmet need, failure of others, unexpected results, skepticism of experts, copying by competitors, industry praise, and licensing.
Establish nexus—tie the evidence to the claimed features, not to a brand, price, or unclaimed feature (Demaco Corp. v. F. Von Langsdorff Licensing Ltd., 851 F.2d 1387 (Fed. Cir. 1988)).
Present indicia via declaration (executive for sales/market share; technologist for unexpected results; industry figure for skepticism).
Insist the indicia be weighed as part of the obviousness determination, not as an after-the-fact tiebreaker (In re Cyclobenzaprine Hydrochloride, 676 F.3d 1063 (Fed. Cir. 2012); Apple Inc. v. Samsung Electronics Co., 839 F.3d 1034 (Fed. Cir. 2016) (en banc)).

Phase 8 — Decide on amendment vs. argument

Argue first where you can—a clean argument keeps full scope at no estoppel cost.
If you amend, add a limitation the combined art genuinely does not teach, supported by the original specification, that still reads on your commercial embodiment.
Remember every narrowing amendment triggers prosecution-history estoppel (Festo, 535 U.S. 722 (2002)); keep dependent-claim fallbacks.

Phase 9 — Build the evidentiary record and use the interview

Draft Rule 1.132 declarations that are specific, supported (reasoned, not asserted), and credible; include the 18 U.S.C. § 1001 acknowledgment if styled as a declaration.
Request an examiner interview to test a proposed amendment and dispel misunderstandings before committing them to the record.
Observe the duty of candor: disclose material prior art known to you; do not overstate what a reference lacks.

Phase 10 — Know the forum and its burden

In prosecution, the examiner must make the prima facie case before the burden shifts to you.
At the PTAB, factual findings are reviewed for substantial evidence; the legal conclusion of obviousness de novo.
In district court, an issued patent is presumed valid and a challenger must prove obviousness by clear and convincing evidence.

Common mistakes

Conceding the prima facie case instead of testing whether it was ever properly made.
Treating a KSR rationale as self-proving—every rationale has predicates.
Offering secondary-considerations evidence with no nexus to the claims.
Reflexive amendment that whittles claims into commercially worthless scope.
Conflating motivation with reasonable expectation of success.

Primary authority

35 U.S.C. § 103. MPEP §§ 2141–2145 (obviousness), 2143 (rationales), 2143.02 (reasonable expectation of success).
Graham v. John Deere Co., 383 U.S. 1 (1966); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007); In re NuVasive, Inc., 842 F.3d 1376 (Fed. Cir. 2016); Arendi S.A.R.L. v. Apple Inc., 832 F.3d 1355 (Fed. Cir. 2016); In re Kubin, 561 F.3d 1351 (Fed. Cir. 2009); In re Gurley, 27 F.3d 551 (Fed. Cir. 1994); In re Gordon, 733 F.2d 900 (Fed. Cir. 1984); Demaco Corp. v. F. Von Langsdorff Licensing Ltd., 851 F.2d 1387 (Fed. Cir. 1988); Apple Inc. v. Samsung Electronics Co., 839 F.3d 1034 (Fed. Cir. 2016) (en banc).

This checklist is general information, not legal advice. Consult a registered patent practitioner.