Martinez v. Ryan, 566 U.S. 1 (2012), was a United States Supreme Court case about ineffective assistance of counsel claims which allowed a narrow exception to Coleman v. Thompson.

There was no dispute that Arizona's preclusion rule barring "successive petitions" was an independent and adequate state ground; federal courts would have no jurisdiction to hear the ineffective assistance claim unless the defendant showed cause for the default.

Martinez then petitioned the district court arguing that ineffective assistance of counsel in the first post-conviction proceeding excused the procedural default.

On March 20, 2012, the Supreme Court issued a 7–2 decision written by Justice Anthony Kennedy, holding that procedurally defaulted ineffective assistance claims are not barred where state law requires the claim to be raised in a post-conviction collateral proceeding and there was no counsel appointed or the counsel in an initial-review collateral proceeding was ineffective under Strickland.

[8][9] Coleman held that attorney error in post-conviction appeals was not cause to excuse procedural default but did not apply "in those cases where state collateral review is the first place a prisoner can present a challenge to his conviction".

[11] Gallow does not foreclose possibility that a district court would excuse the procedural default when state habeas counsel does not raise any ineffective assistance claim.

The Eighth Circuit ruled in Dansby v. Norris that "Martinez" does not apply in states that allow ineffective assistance claims on direct appeal.

At least some district courts have continued after Martinez to deny claims that are contradicted by the record, do not allege facts that would entitle a petitioner to relief or fail to show prejudice.