Inter Partes Review Strategy: Discretionary Denial, Estoppel, and the Parallel District Court Case

Document type: Article Practice area: Intellectual Property — Patents Jurisdiction: United States (federal) Last reviewed: 5 September 2026

A client asks the obvious question: the patent asserted against us is invalid over prior art we can prove. Why would we not file an IPR?

Four reasons, and each of them has ended a case.

The Board may not institute. Institution is discretionary, and a substantial number of petitions are denied — some on the merits, some for reasons that have nothing to do with the merits.

Estoppel. If the Board reaches a final written decision, you cannot assert in district court any ground you raised or reasonably could have raised. For a defendant whose invalidity case is built on patents and printed publications, that can be the entire defense.

The Board cannot decide most of what matters. No non-infringement. No eligibility under 35 U.S.C. § 101 in an IPR. No prior public use or on-sale art. No inequitable conduct. No damages.

And the district court may not stay. A defendant that files an IPR and does not get a stay is litigating on two tracks at once, at roughly 130 percent of the cost of one.

The answer to the client's question is therefore not "yes" or "no" but a structured analysis, and this article sets out its parts.

What an IPR is

The proceeding. A third party petitions the Patent Trial and Appeal Board to cancel one or more claims of an issued patent. Under 35 U.S.C. § 311, the grounds are limited to §§ 102 and 103, and only on the basis of patents and printed publications.

Who may file. Anyone other than the patent owner, subject to the bars below.

The threshold. Section 314(a) permits institution only if the petition shows a reasonable likelihood that the petitioner would prevail on at least one challenged claim.

The schedule. Section 316(a)(11) requires a final written decision within one year of institution, extendable by six months for good cause. Adding the roughly six months from filing to the institution decision, the total is about eighteen months — far faster than most district court cases.

The burden. Preponderance of the evidence, under § 316(e). In district court, invalidity must be proved by clear and convincing evidence under § 282. This difference is the single largest reason petitioners prefer the Board.

The decisionmaker. A panel of three administrative patent judges, technically trained, who read the prior art themselves.

Claim construction. The Board applies the same standard as a district court — the ordinary and customary meaning framework — rather than the broadest reasonable interpretation it once used. This alignment reduced, but did not eliminate, the risk of inconsistent constructions across forums.

The constitutional and structural questions, settled

Three Supreme Court decisions removed the existential challenges to the system, and practitioners should know what each holds because clients still ask.

Oil States Energy Services, LLC v. Greene's Energy Group, LLC, 584 U.S. 325 (2018) held that inter partes review does not violate Article III or the Seventh Amendment. A patent is a public franchise, and its grant involves public rights that Congress may authorize an agency to reconsider. The Court was careful to note the narrowness of its holding — it did not address retroactivity, due process, or takings — but the basic architecture survived.

Cuozzo Speed Technologies, LLC v. Lee, 579 U.S. 261 (2016) held that § 314(d)'s statement that the institution determination is "final and nonappealable" means what it says: the decision to institute is generally not reviewable. The Court left room for review of claims that the Board acted outside its statutory limits or in violation of the Constitution, but the ordinary institution decision is not appealable.

Thryv, Inc. v. Click-To-Call Technologies, LP, 590 U.S. 45 (2020) extended that to the one-year time bar of § 315(b). A determination that a petition was timely — even if wrong — is part of the institution decision and is not appealable. This surprised many practitioners and it means a patent owner's time-bar argument must succeed at the Board or not at all.

United States v. Arthrex, Inc., 594 U.S. 1 (2021) held that the unreviewable authority of administrative patent judges violated the Appointments Clause, and cured it by making Board decisions subject to discretionary review by the Director. The practical result is Director Review — a request for rehearing by the Director of a final written decision or, in some circumstances, an institution decision — which is now a real, if rarely granted, step in the process.

SAS Institute and all-or-nothing institution

For its first several years, the Board routinely instituted on some claims and some grounds and denied others, producing partial institutions.

SAS Institute Inc. v. Iancu, 584 U.S. 357 (2018) ended that. Section 318(a) requires the Board to issue a final written decision "with respect to the patentability of any patent claim challenged by the petitioner." The Court read that literally: if the Board institutes, it must address every claim the petitioner challenged.

The Board subsequently extended the principle to grounds: institution is now all claims and all grounds, or none.

Why this matters strategically:

For petitioners. A petition with one strong ground and three weak ones now risks denial of the whole petition, because the Board assesses the petition as a unit. Petitions have become tighter and more selective.

For estoppel. All-or-nothing institution means a final written decision addresses every ground in the petition, which expands the estoppel that attaches. There is no longer a category of "raised but not instituted" grounds that escaped estoppel.

For the parallel case. A defendant that must choose its grounds carefully at the petition stage is making an early, binding decision about which prior art to use where.

The bars

Three provisions can end a petition before the merits.

The one-year bar — § 315(b). A petition may not be instituted if it is filed more than one year after the petitioner, the real party in interest, or a privy was served with a complaint alleging infringement of the patent.

What counts as service. A complaint that is later dismissed without prejudice generally does not start the clock, on the theory that the dismissal renders the action a nullity. A complaint dismissed with prejudice does. Declaratory judgment complaints filed by the petitioner do not trigger the bar.

Real party in interest and privity. This is where the bar is litigated. A petitioner must identify all real parties in interest, and a patent owner will argue that an unnamed party — an indemnitor, a supplier, a customer, a member of a joint defense group, a corporate parent — was served more than a year ago and is a real party in interest or a privy. Get this right in the petition; an incorrect identification can be fatal, and it cannot be cured after the bar date.

And note Thryv: a Board determination that the petition was timely is not appealable, so this argument must win at the Board.

The civil action bar — § 315(a). A petition may not be filed if the petitioner previously filed a civil action challenging the validity of a claim of the patent. A counterclaim of invalidity does not count.

The stay provision. If the petitioner files a declaratory judgment action after filing the petition, that action is automatically stayed under § 315(a)(2) unless specified conditions are met.

Standing. Unlike district court, no case or controversy is required to file. Anyone may petition — which is why competitors, industry groups, and hedge funds have filed. But note that appealing an adverse final written decision to the Federal Circuit does require Article III standing, and a petitioner with no injury may win at the Board and be unable to appeal a loss.

Discretionary denial

The Board may decline to institute even where the petition meets the threshold. This is the single largest strategic variable in modern PTAB practice, and it is the least stable.

The statutory foundation. Section 314(a) says the Director "may" institute; nothing requires it. Section 325(d) expressly permits the Board to reject a petition where "the same or substantially the same prior art or arguments previously were presented to the Office."

The two recurring categories:

Parallel litigation

Where a district court case involving the same patent is advanced, the Board has considered whether instituting would be an efficient use of resources. The factors the Board has weighed:

Whether the district court has granted a stay or is likely to.
The proximity of the trial date to the Board's projected final written decision date.
The investment in the parallel proceeding by the court and the parties.
The overlap between the issues in the petition and the district court case.
Whether the petitioner and the district court defendant are the same party.
Other circumstances, including the merits of the petition.

The practice has moved. The Office's guidance in this area has been revised more than once, with periods of relatively aggressive discretionary denial and periods in which the Board has been directed to institute where the merits are strong regardless of the trial date. Practitioners must check the current guidance before filing, because the answer has changed materially within a single patent's litigation life.

The reliable operational responses, whatever the current posture:

File early. A petition filed three months after the complaint faces a very different analysis than one filed at eleven months.
Offer a stipulation. A petitioner that stipulates it will not pursue in district court the grounds raised in the petition — or, more broadly, any ground it reasonably could have raised — substantially reduces the overlap concern. This is the most effective single tool available.
Move for a stay in the district court promptly, and tell the Board you have.
Lead with the merits. A strong petition is the best answer to discretion.

Previously presented art — § 325(d)

Where the same or substantially the same art or arguments were before the examiner, the Board may decline. The analysis asks whether the art or arguments are materially the same as those previously presented, and if so, whether the petitioner has shown the Office erred in a material way.

The practical response. If your best art was cited during prosecution, explain specifically what the examiner did not appreciate — a claim limitation not addressed, a teaching in the reference not discussed, a combination not considered. A petition that re-argues art the examiner allowed over, without identifying the error, invites denial.

Estoppel

This is the cost, and it is frequently underestimated.

Section 315(e) provides that a petitioner in an IPR that results in a final written decision may not assert, in a district court action or an ITC proceeding, that the claim is invalid on any ground that the petitioner raised or reasonably could have raised during the IPR.

What "reasonably could have raised" means. The prevailing understanding is that it covers grounds a skilled searcher conducting a diligent search reasonably could have been expected to discover. That is a broad standard, and it reaches art the petitioner did not find but should have.

What estoppel does not reach:

Grounds outside the IPR's scope. Prior public use, on-sale activity, and system prior art cannot be raised in an IPR under § 311, so estoppel does not bar them. This is the principal escape hatch, and it drives defendants to develop system art.
Section 101 eligibility, which cannot be raised in an IPR.
Section 112 written description, enablement, and indefiniteness.
Inequitable conduct.
Non-infringement, obviously.
Grounds where no final written decision issued — a denied petition, a settled proceeding, or a withdrawn petition creates no estoppel.

Who is estopped. The petitioner, the real party in interest, and privies. This is why real-party identification matters in both directions: naming a party creates estoppel against it, and failing to name one can invalidate the petition.

The strategic consequence. A defendant whose invalidity case rests entirely on patents and printed publications is choosing between forums, not adding one. A defendant with system prior art, a § 101 argument, or a strong § 112 position retains a meaningful district court case regardless.

Timing note. Estoppel attaches on the final written decision, not at institution. A settlement before the final written decision avoids it entirely, which is why many IPRs settle in the months before the hearing.

The stay

An IPR is worth far more to a defendant if the district court stays the case, and far less if it does not.

The factors courts apply:

Whether a stay will simplify the issues and streamline trial.
Whether discovery is complete and a trial date has been set.
Whether a stay would unduly prejudice or present a clear tactical disadvantage to the non-moving party.

Some courts add a fourth: whether a stay will reduce the burden of litigation on the parties and the court.

What moves the analysis:

Timing. A motion filed shortly after institution, early in the case, is far more likely to succeed than one filed after the close of fact discovery.
Institution. Most courts will not stay before the Board institutes; many will after. Filing the petition early is therefore doubly valuable.
Claim overlap. A petition covering every asserted claim simplifies more than one covering half.
The parties' relationship. A patent owner that practices the invention and competes with the defendant has a stronger prejudice argument than a non-practicing entity whose remedy is money.
A stipulation. Offering to be bound in district court by the Board's determinations, or to drop the petition's grounds, materially improves the motion.

The ITC is different. Section 337 investigations proceed on a statutory schedule and the Commission does not stay for a co-pending IPR. A respondent facing an ITC investigation and filing an IPR is running two full proceedings in parallel, with the ITC almost certainly finishing first.

Motions to amend

A patent owner may move to amend the claims under § 316(d), and the practice deserves a candid description: it rarely works.

The requirements. A reasonable number of substitute claims, no broadening, and support in the original disclosure. The patent owner bears a duty of candor and must address the prior art of record.

Why success rates are low. The substitute claims face the same prior art plus whatever else the petitioner finds, on a compressed schedule, before judges who have already read the art. And a patent owner proposing amendments is implicitly conceding the original claims are vulnerable.

The Board's pilot program permitting preliminary guidance on a motion to amend, and a further opportunity to revise, has improved outcomes somewhat. It is worth using where an amendment is contemplated.

The intervening rights problem. Substitute claims that are not substantially identical to the originals create intervening rights, which can eliminate past damages entirely. A patent owner that amends to survive may win a patent worth much less than the one it had.

The practical guidance for patent owners. Treat the motion to amend as a genuine fallback rather than a reflex, model the intervening rights consequence before filing it, and consider whether a continuation application — filed before the IPR, while the family is still pending — is the better tool.

What the parallel case looks like

A defendant running both tracks faces specific coordination problems.

Claim construction. The Board and the district court now apply the same standard, but they can still reach different results, and the parties' own positions are the risk. A narrow construction argued at the Board to distinguish prior art will be quoted against the defendant on infringement; a broad construction argued in district court to capture the accused product will be quoted at the Board. Assign one person to review every filing in both forums for consistency. This is the most common self-inflicted wound in dual-track practice.

Expert consistency. The same technical expert frequently appears in both proceedings, and inconsistent testimony is discoverable and devastating.

Discovery asymmetry. PTAB discovery is limited — routine discovery of exhibits and cross-examination of declarants, plus additional discovery only in the interests of justice. District court discovery is broad. Material obtained in district court can be used at the Board, subject to the protective orders in each.

Timing. The Board's eighteen-month clock frequently runs alongside a district court case scheduled for trial at month twenty-four to thirty. Where the Board finishes first and cancels the claims, the district court case ends. Where the district court finishes first, the Board may terminate as to the losing party.

Settlement. Settling the district court case does not automatically terminate the IPR — the Board may proceed to a final written decision in the public interest, particularly after institution. Any settlement should address the IPR expressly, and the parties must file the settlement agreement with the Board.

A decision framework for petitioners

Run these questions in order.

1. Is the invalidity case built on patents and printed publications? If it depends on prior public use, on-sale activity, or system art, the Board cannot hear it and estoppel will not reach it. That argues for district court.

2. Would estoppel cost the district court invalidity defense? If the answer is "we would have nothing left," the calculus is very different. If system art or § 112 or § 101 arguments survive, the cost is bounded.

3. Is the primary defense non-infringement? The Board cannot decide it. A defendant winning on non-infringement gets nothing from an IPR except cost.

4. Are we within the one-year bar, and is the real-party analysis clean? Identify every entity that has been served, every indemnitor, every supplier, and every joint defense member. Get it right the first time.

5. What is the district court trial date, and will the court stay? File early. A petition at month three with a stay motion behind it is a different proposition than one at month eleven.

6. Was our best art before the examiner? If so, prepare the § 325(d) answer: what specifically did the Office get wrong?

7. Can we stipulate? A stipulation not to pursue the petition's grounds in district court is the most effective single response to discretionary denial concerns.

8. What does it cost, and against what? An IPR runs several hundred thousand dollars through a final written decision. Compare against the cost of the same invalidity fight in district court, discounted by the probability of a stay.

9. And who else is affected? A defendant in a multi-defendant case should consider a joint petition. Cost sharing is substantial, and joinder under § 315(c) permits later parties to join an instituted proceeding — with its own timing rules and its own estoppel consequences.

The patent owner's playbook

Before institution — the preliminary response.

The patent owner may file a preliminary response within three months of the notice of filing date, and it is frequently the highest-leverage document in the proceeding. Roughly a third of petitions are denied institution, and the preliminary response is where that happens.

What to argue, in order of practical effect:

The bars. The one-year bar under § 315(b), with a real-party-in-interest or privity argument. Identify every entity that was served more than a year ago and every relationship — indemnity, supply, joint defense, corporate — connecting it to the petitioner.
Discretionary denial. The parallel litigation posture and the § 325(d) previously-presented-art argument. Check the current guidance; this ground has moved.
The merits. Why the petition fails the reasonable-likelihood threshold: a missing limitation, an unsupported motivation to combine, a misreading of the reference.
Deficiencies in the petition. Incomplete claim charts, unexplained expert conclusions, grounds that are redundant or inadequately articulated. Because institution is now all or nothing after SAS, a defect in one ground can sink the petition.

Testimonial evidence. A patent owner may now submit a declaration with the preliminary response, subject to the rule that genuine factual disputes are viewed in the petitioner's favor at institution. Use it where the declaration establishes a fact rather than an opinion.

After institution — the response.

Attack the motivation to combine. In practice this is where more IPRs are won than on any missing-element argument. A petition that combines three references without a technically grounded reason is vulnerable.
Attack the expert. Cross-examination of the petitioner's declarant is the patent owner's principal discovery tool. Use it to establish what the reference does not teach and what the expert did not consider.
Develop secondary considerations. Commercial success, long-felt need, failure of others, industry praise, copying, and skepticism — with a nexus to the claimed features. The Board takes these seriously when they are supported.
Consider the motion to amend deliberately, with the intervening rights consequence modeled.

Throughout — the parallel case. Everything the patent owner says at the Board about claim scope will be used in district court. A narrow construction adopted to avoid prior art may defeat infringement.

A worked decision

Bellwood Instruments is sued by Kestrel IP Holdings, a non-practicing entity, on two patents covering a sensor calibration method. The complaint is filed in the Western District of Texas. Bellwood's counsel, Priyanka Osei-Lindqvist, runs the analysis in the first month.

Question 1 — what is the invalidity case? Two strong printed publications and one strong piece of system prior art: a competitor's product sold three years before the priority date, documented by manuals, purchase orders, and a former employee willing to testify.

Question 2 — estoppel cost. The printed publications would be estopped. The system art would not, because § 311 limits IPR to patents and printed publications. Bellwood would retain a real invalidity defense in district court either way.

Question 3 — non-infringement. Moderate. Bellwood's calibration runs at a different point in the cycle, but the claim language is broad. Not a defense to rely on alone.

Question 4 — bars. Bellwood was served two months ago. But its supplier, Thackery Components, was served on the same patents fourteen months ago and has an indemnity obligation to Bellwood. Priyanka's analysis: Thackery is likely a real party in interest, which would time-bar a petition. This nearly ends the inquiry. She structures the petition to be filed by Bellwood alone, documents the absence of Thackery's control or funding, and names Thackery as an RPI out of caution — accepting the estoppel consequence for Thackery rather than risking the petition.

Question 5 — trial date and stay. The district court's schedule sets trial at month twenty. A final written decision would issue around month twenty-two if the petition is filed now. That is the worst possible configuration for discretionary denial.

The responses: file immediately, at month three rather than month eleven; move for a stay the week after filing; and offer a broad stipulation not to pursue in district court any ground raised or reasonably could have been raised in the petition.

Question 6 — § 325(d). One of the two publications was cited in an IDS but never applied by the examiner. The petition explains specifically that the examiner never addressed the reference's teaching of the disputed limitation.

The outcome. Institution granted at month nine. The district court stays the case at month ten, citing the stipulation and the early filing. Final written decision at month twenty-one cancels all challenged claims of one patent and upholds the other. The parties settle at month twenty-three, with Bellwood's remaining exposure limited to the surviving patent — against which it retains the system art.

Priyanka's retrospective: "The stipulation bought the stay, and the stay was the whole value. Filing at month eleven would have cost us both."

What to tell a client

An IPR is a forum choice, not a supplement. If your invalidity case is printed-publication art, you are choosing where to have that fight.

The economics are genuinely favorable where the choice makes sense: a few hundred thousand dollars and eighteen months, at a preponderance standard, before technical judges, versus several million dollars and three years at clear and convincing evidence before a jury.

The variables that decide it are the estoppel cost, the availability of a stay, and the discretionary denial posture — and two of those three improve dramatically if you file early.

File early. It is the single most repeated piece of advice in this practice and the most frequently ignored, because clients want to see the infringement contentions first. The cost of waiting is a materially worse discretionary posture and a materially worse stay motion.

And check the current guidance. Discretionary denial practice has moved more than once, and a strategy built on last year's framework may be wrong.

The other post-grant proceedings

IPR is the dominant vehicle, but three others exist and each has a niche.

Post-grant review — § 321. Available only for patents with an effective filing date on or after March 16, 2013, and only within nine months of issuance. Its scope is far broader than IPR: any ground of invalidity, including § 101 eligibility, § 112 written description and enablement, and prior public use and on-sale art.

Why it is rarely used. The nine-month window closes long before most patents are asserted, so by the time a defendant wants to challenge a patent, PGR is unavailable. Its practical use is by competitors monitoring a rival's issuances.

Its estoppel is broader, matching its scope — which is a reason for caution when it is available.

Institution threshold: more likely than not that at least one claim is unpatentable, or a novel or unsettled legal question important to other patents — a marginally higher and differently framed standard than IPR's reasonable likelihood.

Ex parte reexamination. Any person, including the patent owner, may request reexamination on patents and printed publications. It is inexpensive, it can be requested anonymously, and — critically — it creates no estoppel for a third-party requester who does not participate.

Why it is underused. The requester has no participation rights after the request; the proceeding is between the examiner and the patent owner. That is a real disadvantage, but for a defendant already estopped by an IPR, or one that wants a low-cost, low-risk challenge without estoppel, it remains a tool.

Derivation proceedings — § 135. Replaced interference practice under the first-inventor-to-file system. Rare, and available only to an applicant claiming that an earlier applicant derived the invention from the petitioner's inventor.

Choosing among them. The practical decision tree: if the patent is within nine months of issuance and you have a § 101 or § 112 argument, consider PGR. If the patent is older and your art is printed publications, consider IPR and model the estoppel. If you want a challenge without estoppel and can live without participation, consider ex parte reexamination. Otherwise, litigate in district court.

Where the practice is unsettled

Discretionary denial. The single most volatile area. Office guidance has been issued, rescinded, and reissued, and the current posture must be checked before every filing decision. A strategy built on the framework in place two years ago may produce the opposite result today.

The scope of "reasonably could have raised." The estoppel standard's outer boundary — particularly whether it reaches system prior art that could have been described in a printed publication — continues to be litigated, with district courts reaching different results.

Real party in interest and privity. The doctrine has developed substantially and remains fact-intensive, and after Thryv a Board determination is unreviewable — which raises the stakes on getting it right in the petition.

Director Review after Arthrex. The scope and standards of the Director's discretionary review are still developing, including whether and when it reaches institution decisions.

Standing to appeal. A petitioner without Article III injury may prevail at the Board and be unable to appeal a loss, and the boundaries of what constitutes sufficient injury for a competitor or a licensee continue to be worked out.

Practical instruction. In an area this unsettled, the durable advice is procedural rather than doctrinal: file early, identify real parties carefully, stipulate where it helps, keep positions consistent across forums, and re-check the guidance before every decision.

The one-page summary

What an IPR is: an administrative challenge to an issued patent on §§ 102 and 103 grounds, limited to patents and printed publications, decided by three technical judges at a preponderance standard within about eighteen months of filing.

Why petitioners want it: the burden is preponderance rather than clear and convincing, the judges read the art themselves, and it costs a fraction of a district court invalidity case.

What it cannot do: decide non-infringement, eligibility under § 101, § 112 grounds, inequitable conduct, or invalidity based on public use, on-sale activity, or system prior art.

The three gates: the one-year bar of § 315(b), including real parties and privies; the institution threshold of § 314(a); and discretionary denial, which is the least predictable variable in the practice.

The price: § 315(e) estoppel on any ground raised or reasonably could have been raised, attaching on the final written decision.

The multiplier: a district court stay. Without one, you are running two proceedings.

The four things that improve every variable: file early, identify real parties correctly, offer a stipulation, and move for a stay immediately after institution.

The structural constants after 2018: institution is all claims and all grounds or none, per SAS; the institution decision is unreviewable, per Cuozzo and Thryv; the system is constitutional, per Oil States; and the Director may review final decisions, per Arthrex.

And the sentence to give a client: an IPR is not an additional defense. It is a choice about where to have the invalidity fight, and the choice is usually irreversible.

Frequently asked questions

How much does an IPR cost? Roughly $350,000 to $700,000 through a final written decision for a single patent, including expert work, plus government fees. A district court invalidity case on the same art runs several times that.

What are the odds? Roughly two-thirds of petitions that reach an institution decision are instituted, and of instituted proceedings that reach a final written decision, a substantial majority result in at least some claims being cancelled. The composite figure most often quoted — the share of all filed petitions that end with all challenged claims cancelled — is considerably lower, because denials and settlements remove most petitions before that point. Ask which denominator a statistic uses.

Can we file after being sued? Yes, within one year of service of the complaint under § 315(b) — counting service on you, on any real party in interest, and on any privy. File early within that year, not late.

Does the district court have to stay? No. Stays are discretionary and depend heavily on timing, institution, claim overlap, and whether the patent owner is a competitor.

Can we challenge eligibility at the Board? Not in an IPR — § 311 limits it to §§ 102 and 103 on patents and printed publications. Only in a post-grant review under § 321, which requires a post-March 2013 filing date and a petition within nine months of issuance.

What happens to our district court defenses if we lose? Section 315(e) estoppel bars grounds you raised or reasonably could have raised. It does not reach system prior art, public use, on-sale activity, § 101, § 112, inequitable conduct, or non-infringement.

Can we avoid estoppel by settling? Yes, if you settle before the final written decision. Estoppel attaches on the decision, not at institution, which is why many proceedings settle in the months before the hearing.

Should we name our supplier as a real party in interest? If it funds, directs, or controls the petition, or if it is a privy, you must. Getting this wrong can invalidate the petition, and after Thryv the Board's determination is unreviewable. Err toward disclosure and accept the estoppel consequence.

Can the patent owner fix the claims? It can move to amend under § 316(d), and it rarely succeeds. Substitute claims also create intervening rights that can eliminate past damages.

Can we appeal a denial of institution? Generally no. Cuozzo and Thryv foreclose review of the institution decision, including the time-bar determination. Director Review after Arthrex is the remaining avenue and it is discretionary.

What is the single most important tactical decision? When to file. Everything else — discretionary denial, the stay, the trial date comparison — improves if the petition is on file in month three rather than month eleven.