In the case, the Court settled a circuit split regarding the reach of the federal aggravated identity theft statute.

§ 1028A, the federal aggravated identity theft statute, states: Whoever, during and in relation to any felony violation enumerated [elsewhere in the statute], knowingly transfers, possesses, or uses, without lawful authority, a means of identification of another person, shall, in addition to the punishment provided for such felony, be sentenced to a term of imprisonment of 2 years.

The Hector Garza Center, a youth emergency shelter near San Antonio, hired PARTS to perform psychological assessments for its patients.

Based on that finding, PARTS would either file a Medicaid reimbursement claim for its services, or it would bill Garza.

The government did not contest Dubin's ability to lawfully use Patient L's name to file the Medicaid bill.

A three-judge panel found that the statute operated as a two-part question for determining criminal activity: Did the defendant use a means of identification (as defined in § 1028(d)(7))?

Judge Richman also acknowledged that the text of the statute provides criminal penalties for Dubin's actions, notwithstanding the fact that his conduct falls outside the common conception of "identity theft".

A more reasonable reading of § 1028A, Costa argued, would confine the statute to what is commonly understood to constitute identity theft.

It held that a defendant "uses" another person's identity "in relation to" a predicate offense when the use is "at the crux" of what makes the conduct criminal.

[13] While the Fifth Circuit had relied on the general, dictionary definitions of "use" and "in relation to', Sotomayor cites prior Supreme Court precedent stating that the meanings of these terms is heavily dependent on context.

The contextual approach is further supported, Sotomayor argues, by the fact that the statutory language uses two such context-dependent terms.

§ 1028AA broader reading of the statute, one that ignores the title its common meaning, would include, Justice Sotomayor argues, things with little relation to identity theft, such as overbilling.

Citing prior Supreme Court precedent, Sotomayor states that the third verb, "uses", due to its proximity to the other two should be understood to have a meaning similar to "transfer" and "possess".

A narrow reading of the statute supports the notion that the use of three verbs is meant to capture the complex form that identity theft may take.

In such a case, generic overbilling that happens to involve means of identification would automatically trigger a 2-year mandatory minimum sentence.

Sotomayor argues that attributing such a sweeping meaning to an opaquely worded statute would be at odds with prior precedent.

[15] Justice Gorsuch filed an opinion concurring in the judgment He agreed that Dubin's conviction should be overturned, not because the government had relied on too broad a reading of § 1028A, but because the statute itself is so vaguely worded as to deprive potential offenders of fair notice and due process.

Turning back to the facts of the case, Gorsuch argues that Patient L's identity could reasonably be inferred to be "at the crux" of the fraud, since it was an integral part of the crime – without it, Dubin could not have submitted the Medicaid bill.

Despite the Court's attempts, he argues that the majority opinion does not do enough to specify which conduct constitutes aggravated identity theft, a problem that - he says - Congress alone can fix.