What Does It Mean When Sentences Run Concurrently?

When a judge orders sentences to run concurrently, it means every sentence starts on the same day and runs on the same clock, so the person serves only as long as the single longest term rather than adding the terms together. A five-year sentence and a three-year sentence imposed concurrently come out to five years of prison time, because the shorter term is absorbed by the longer one. The opposite structure, consecutive sentencing, stacks the same two terms end-to-end for a total of eight years.¹

That one choice often matters more than the length of any individual count.

Concurrent and Consecutive, Side by Side

Concurrent sentences all run at once. A person given 10 years, 7 years, and 3 years to run concurrently serves 10 years, not 20. Consecutive sentences do the opposite: each term must be fully served before the next begins, so that same combination becomes a 20-year stretch. Prison officials treat the combined sentences as one aggregate term for administrative purposes, but the underlying math is what shapes a person’s life.¹

What the Default Is in Federal Court

Federal law sets a default that depends on timing. When a judge imposes multiple prison terms at the same sentencing, those terms run concurrently unless the judge says otherwise or a statute requires stacking. When a person is already serving a sentence and picks up a new conviction, the default flips: the new sentence runs consecutively unless the judge affirmatively orders concurrent time.¹

One rule is absolute. A court cannot impose consecutive sentences for an attempt and the completed offense that was the sole objective of that attempt. Convictions for both attempted bank robbery and the bank robbery itself have to run concurrently.¹

State rules vary. Some states follow a similar default-concurrent approach, others presume consecutive sentences, and others leave it entirely to the judge with no default at all. Anyone facing multiple charges in state court should check the specific rule in that jurisdiction.

What a Judge Weighs

Federal judges apply the same sentencing factors in 18 U.S.C. § 3553(a) when deciding whether to run terms together or stack them.² A few questions tend to drive the decision:

Whether the offenses arose from a single event or were separate decisions to break the law. Related conduct is more likely to draw concurrent terms; unrelated crimes committed weeks apart are not.
The defendant’s criminal history. A clean record weighs toward concurrency; a long record pushes toward consecutive terms as a deterrent.
The danger the defendant poses to the public going forward.
Whether the total punishment is proportional to the conduct and consistent with sentences other defendants have received in similar cases.

Violent offenses that caused serious harm to victims are the most common drivers of consecutive sentences. Victims themselves have a federally protected right to be heard on this question at the sentencing hearing, and a victim’s statement about the harm can carry real weight when the judge is deciding how to structure the time.³

The structure is also one of the most heavily negotiated pieces of a plea deal. A prosecutor’s agreement to recommend concurrent sentences is often the main reason a defendant takes an offer, because the structure can matter more to the client than the number of years on any individual count.

When Concurrent Isn’t an Option

Some federal statutes strip the judge of discretion and require the sentence to run consecutively to everything else. Two show up often.

The first is 18 U.S.C. § 924(c), which applies when someone uses, carries, or possesses a firearm during a crime of violence or a drug trafficking offense. The added term, which starts at a five-year minimum and climbs sharply for brandishing, firing, certain weapon types, machine guns, and repeat convictions, cannot run concurrently with the sentence for the underlying crime.⁴ This is where federal sentences that look impossibly long often come from: the gun count alone can dwarf the sentence for the crime it accompanied.

The second is 18 U.S.C. § 1028A, aggravated identity theft. A conviction adds a mandatory two years (five if the underlying crime is terrorism-related), and the statute explicitly bars the term from running concurrently with any other sentence, including the sentence for the crime during which the identity theft happened. The judge also cannot shorten the underlying sentence to offset the add-on. The one bit of flexibility: when a defendant is convicted of multiple § 1028A counts, those counts can run concurrently with each other.⁵

State and Federal Sentences at the Same Time

When a person faces both a state sentence and a federal sentence, there is no automatic rule that one runs alongside the other. Whichever sovereign took custody first generally holds the person first, and if the federal sentencing judge says nothing about the state sentence, the Bureau of Prisons treats the federal time as consecutive.

Federal judges do have authority to order a federal sentence to run concurrently with a state sentence, including a state sentence that has not yet been imposed. The Supreme Court confirmed that discretion in Setser v. United States.⁶ The U.S. Sentencing Guidelines give more detail: if the federal crime was committed while the person was already serving the state term, the guidelines call for consecutive sentences; if the state offense is closely related to the federal one as “relevant conduct,” the sentence should generally run concurrently, with a credit adjustment for time already served on the state side.⁷ If a federal sentence should run concurrently with a state one, the defense needs to raise it at the federal sentencing hearing, not afterward.

What Concurrent Means for the Actual Release Date

Concurrent structure shortens the clock, and two other mechanics then operate on top of it.

Pretrial detention counts. Federal law requires credit toward the sentence for any time spent in official detention before the sentence begins, as long as that time relates to the offense being sentenced or a charge arising from the same conduct. The same days cannot be credited to more than one sentence, which matters most when state and federal cases overlap: pretrial time already credited to the state sentence will not be credited again to the federal one.⁸

Good conduct time then applies to the aggregate. The Bureau of Prisons treats multiple sentences, whether concurrent or consecutive, as a single combined term for administrative purposes.¹ For federal offenses committed after November 1, 1987, inmates can earn up to 54 days of good conduct credit per year of the sentence imposed if they are making satisfactory progress toward a GED or high school diploma, and 42 days per year otherwise.⁹ On a 10-year concurrent sentence, that credit can shave roughly 540 days off the release date. The same offenses stacked to 15 years consecutively build credit on a bigger number but still keep the person in prison far longer.

Changing a Sentence After It’s Imposed

Switching a sentence from consecutive to concurrent after the fact is very hard. Federal courts have narrow authority to modify a prison sentence once pronounced: a reduction for substantial assistance to the government, a reduction for extraordinary and compelling circumstances such as terminal illness, or a reduction when the Sentencing Commission lowers the applicable range.¹⁰ None of those provisions is a vehicle for restructuring concurrent and consecutive time.

The remaining option is a direct appeal arguing the judge abused discretion or misapplied the sentencing factors, and appellate courts give trial judges significant deference on this call. The fight over whether sentences run together or stack has to be won at the original sentencing hearing or in the plea negotiation that leads up to it.

1
Office of the Law Revision Counsel. 18 USC 3584 – Multiple Sentences of Imprisonment
2
Office of the Law Revision Counsel. 18 USC 3553 – Imposition of a Sentence
3
Office of the Law Revision Counsel. 18 USC 3771 – Crime Victims Rights
4
Office of the Law Revision Counsel. 18 USC 924 – Penalties
5
Office of the Law Revision Counsel. 18 USC 1028A – Aggravated Identity Theft
6
Cornell Law School. Setser v United States
7
United States Sentencing Commission. USSG 5G1.3 – Imposition of a Sentence on a Defendant Subject to an Undischarged Term of Imprisonment or Anticipated State Term of Imprisonment
8
Office of the Law Revision Counsel. 18 USC 3585 – Calculation of a Term of Imprisonment
9
eCFR. Part 523 Computation of Sentence
10
Office of the Law Revision Counsel. 18 USC 3582 – Imposition of a Sentence of Imprisonment