Do You Have to Prove You'll Win to Get a Certificate of Appealability?

No. To appeal the denial of federal habeas relief, you need a certificate of appealability (COA), which is permission to appeal. In Buck v. Davis, the Supreme Court made clear that getting a COA should not require you to prove you will win. You only need to show that your claim is debatable.

The legal standard for a certificate of appealability

A COA may issue only "if the applicant has made a substantial showing of the denial of a constitutional right." 28 U.S.C. § 2253(c)(2).

The Supreme Court has said this is a low bar. You need to show that "jurists of reason could disagree" with the district court, or that the issues "deserve encouragement to proceed further." Miller-El v. Cockrell, 537 U.S. 322, 327 (2003). The court should not do a "full consideration" of the claim at this stage. Id. at 336.

Even so, the original article observed that federal courts had "near uniformly" required prisoners to show probable success on the merits before granting a COA, despite this lax standard. Because of this, the Supreme Court was asked again to clarify the standard. That is what happened in Buck v. Davis, 580 U.S. 100 (2017).

Duane Buck's case

Duane Buck was on death row in Texas. At the penalty phase of his trial, his own lawyer called an expert witness. That witness testified that Buck was more likely to be dangerous in the future because he is Black. The jury sentenced Buck to death.

Buck's state post-conviction lawyer never challenged trial counsel's choice to use that testimony. Later, the Supreme Court decided Martinez v. Ryan, 566 U.S. 1 (2012), and Trevino v. Thaler, 569 U.S. 413 (2013).

Those cases let a state prisoner raise a defaulted claim of ineffective trial counsel in federal court in some situations. The prisoner must show that the post-conviction lawyer was ineffective, or that there was no lawyer, and that the underlying claim "has some merit."

As Buck summarized Martinez, "a prisoner may establish cause for procedural default if (1) the state courts did not appoint counsel in the initial-review collateral proceeding, or appointed counsel in that proceeding . . . was ineffective under the standards of Strickland v. Washington, 466 U.S. 668 (1984); and (2) the underlying . . . claim is a substantial one, which is to say that . . . the claim has some merit." Buck, slip op. at 9.

These rules apply only where the prisoner is required, or effectively required, to raise ineffective assistance of trial counsel for the first time in post-conviction proceedings. Trevino added the "effectively required" category.

Buck then asked the federal court to reopen his habeas case under Federal Rule of Civil Procedure 60(b)(6). That rule allows relief from a judgment in "extraordinary circumstances."

What the Supreme Court held in Buck v. Davis

The district court denied relief. The Fifth Circuit then denied a COA after deciding that Buck had not shown extraordinary circumstances.

The Supreme Court said that was the wrong question. Chief Justice Roberts wrote that the COA inquiry "is not coextensive with a merits analysis."

According to the Chief Justice, "the question for the Fifth Circuit was not whether Buck had 'shown extraordinary circumstances' … Those are ultimate merits determinations the panel should not have reached." He repeated what the Court had said before: a "court of appeals should limit its examination [at the COA stage] to a threshold inquiry into the underlying merit of the claims," and ask "only if the District Court's decision was debatable."

The Court explained:

That a prisoner has failed to make the ultimate showing that his claim is meritorious does not logically mean he failed to make a preliminary showing that his claim was debatable.

In plain terms, a court may not decide the whole appeal and then use that result to deny a COA. When a court "inverts the statutory order of operations and 'first decides the merits of an appeal, . . . then justifies its denial of a COA based on its adjudication of the actual merits,'" it has "placed too heavy a burden on the prisoner at the COA stage." The Court said Miller-El "flatly prohibits" that.

The Court described the statute as a two-step process. First, the court decides whether a claim is reasonably debatable. If it is, the appeal goes forward in the normal way. The Court did not set procedures for every case. But it said that whatever procedures courts use at the COA stage "should be consonant with the limited nature of the inquiry."

The Court then reached the merits itself. Relying on Trevino and other factors, it held that Buck's trial lawyer was ineffective for presenting the race-based testimony. "Our law punishes people for what they do, not who they are. Dispensing punishment on the basis of an immutable characteristic flatly contravenes this guiding principle," the Court wrote. It also held that Buck had shown extraordinary circumstances for Rule 60(b)(6) relief. The case was reversed and sent back.

What Buck means for federal prisoners

The Buck COA rule applies to federal prisoners appealing the denial of a 2255 motion. If a court denies a COA because it thinks you will lose, Buck says the question is only whether your claim is debatable.

Martinez and Trevino are a different matter. They were written for state prisoners in § 2254 cases.

The original 2017 article argued that the federal system fits the "effectively required" category. That is because ineffective-assistance claims are usually saved for a 2255 motion rather than raised on direct appeal. See Massaro v. United States, 538 U.S. 500 (2003). On that view, it said Martinez and Trevino were "a new, narrow way" for federal prisoners to reopen their 2255 case, or to seek § 2241 relief, when a substantial ineffective-assistance claim was left out of the first 2255 motion because there was no lawyer or the 2255 lawyer was ineffective.

Note (October 2026): That strategy is not available today, and you should not rely on it. Do not count on Martinez or Trevino to reopen a federal 2255 case. And after Jones v. Hendrix, 599 U.S. 465 (2023), a § 2241 petition is not a way around the limits on second 2255 motions. Under 28 U.S.C. § 2255(h), a second or successive motion needs permission from the court of appeals and must rely on newly discovered evidence or a new constitutional rule the Supreme Court has made retroactive. See our post on ineffective post-conviction counsel.

Facing a federal sentence? Book a consultation to talk it through with Brandon Sample.