OR Rev Stat § 137.370 (2021)
2021 Oregon Revised Statutes|Volume : 04 - Criminal Procedure, Crimes|Chapter 137 - Judgment and Execution; Parole and Probation by the Court|Section 137.370 - Commencement and computation of term of imprisonment in state correctional institution; sentences concurrent unless court orders otherwise.

(1) When a person is sentenced to imprisonment in the custody of the Department of Corrections, the term of confinement therein commences from the day the person is delivered to the custody of an officer of the Department of Corrections for the purpose of serving the sentence executed, regardless of whether the sentence is to be served in a state or federal institution. (2) Except as provided in subsections (3) and (4) of this section, when a person is sentenced to imprisonment in the custody of the Department of Corrections, for the purpose of computing the amount of sentence served the term of confinement includes only: (a) The time that the person is confined by any authority after the arrest for: (A) The crime for which sentence is imposed; (B) A lesser included or greater inclusive offense of the crime for which sentence was imposed; and (C) Any other crime constituting a violation of Oregon law within the same county designated by the sentencing court in the judgment as having been committed as part of the same criminal episode as the crime for which sentence was imposed; and (b) The time that the person is authorized by the Department of Corrections to spend outside a confinement facility, in a program conducted by or for the Department of Corrections. (3) When a judgment of conviction is vacated and a new sentence is thereafter imposed upon the defendant for the same crime, a lesser included or greater inclusive offense of the crime, or any crime constituting a violation of Oregon law within the same county designated by the sentencing court in the judgment as having been committed as part of the same criminal episode as the crime, the period of detention and imprisonment theretofore served shall be deducted from the maximum term, and from the minimum, if any, of the new sentence. (4) Unless the court expressly orders otherwise, a person who is confined as the result of a sentence for a crime or conduct that is not directly related to the crime for which the sentence is imposed, or for violation of the conditions of probation, parole or post-prison supervision, shall not receive presentence incarceration credit for the time served in jail toward service of the term of confinement. (5) Unless the court expressly orders otherwise, a term of imprisonment shall be concurrent with that portion of any sentence previously imposed that remains unexpired at the time the court imposes sentence. This subsection applies regardless of whether the earlier sentence was imposed by the same or any other court, and regardless of whether the earlier sentence is being or is to be served in the same penal institution or under the same correctional authority as will be the later sentence. (6) As used in this section, "criminal episode" has the meaning given that term in ORS 131.505. [Amended by 1955 c.660 §15; 1965 c.463 §19; 1967 c.232 §2; 1973 c.562 §2; 1973 c.631 §4; 1981 c.424 §2; 1987 c.251 §4; 1987 c.320 §35; 1995 c.657 §20; 2015 c.508 §§1,4]