OPINION
{1} Defendant Escolástico Martinez pleaded guilty to, inter alia, a charge of aggravated driving while intoxicated (DWI), third offense, contrary to NMSA 1978, § 66-8-102(F)(2) (1994, prior to 1997 amendment). On this charge, the magistrate court sentenced Martinez to 364 days in jail, suspending 274 days and leaving a remaining jail term of 90 days. The court later entered an amended sentence granting 90 days presentence credit for in-patient alcohol treatment. We conclude that trial courts possess inherent discretionary authority to grant presentence confinement credit, so long as the exercise of discretion does not unduly interfere
I.
{2} On February 14, 1995, Martinez signed a plea and disposition agreement, pleading guilty to a third offense aggravated DWI, contrary to Section 66-8-102(F)(2), and driving with a revoked license, contrary to NMSA 1978, § 66-5-39 (1994). The plea and disposition agreement, signed by the magistrate judge and the prosecutor, contained the following disposition for the DWI charge: “364 days jail with 274 days suspended for 90 days; 1 year supervised probation; random urinalysis; alcohol screening and treatment.” The court ordered Martinez to report to a screening and assessment program. Because the assessment included a recommendation of 90 days in-patient treatment and counseling, Martinez immediately entered an in-patient alcohol treatment program at the Recovery of Alcoholics Program (RAP).
{3} The magistrate court later formally sentenced Martinez in accordance with the plea and disposition agreement. In addition, the court imposed a fine of $750 for the DWI charge. The court also finalized its decision to suspend 274 days of the 364 day sentence and imposed, as part of the suspension, the condition that Martinez successfully complete a 90-120 day treatment program at RAP. Finally, the court entered a commitment to jail for 90 days, scheduled to commence on June 16,1995.
{4} RAP discharged Martinez on June 2, 1995, after successfully completing the treatment program in 106 days. Martinez then moved to amend his sentence to reflect presentence credit for the time he spent in treatment. The court granted Martinez’s motion and allowed 106 days of in-patient treatment in lieu of 90 days jail. Although Martinez also was convicted, under Section 66-5-39, of driving with a revoked license, for which the magistrate court sentenced Martinez to 364 days and suspended 357 days, the trial court did not grant presentence confinement credit on this charge. In the amended judgment and sentence, the court committed Martinez for the remaining seven days jail on the revoked license conviction. Thus, though Martinez was in treatment for 106 days, the court granted presentence confinement credit only with respect to the 90 day sentence for the DWI charge.
{5} The State then appealed the magistrate court’s grant of confinement credit. The district court concluded that court-ordered, compelled attendance at an in-patient treatment program constitutes official confinement for purposes of presentence confinement credit. As a result, the district court affirmed the amended sentence.
{6} After the State appealed the decision of the district court, the Court of Appeals certified the matter to this Court. The Court of Appeals, unlike the parties and the district court, was unwilling to assume that the magistrate court possessed the power to grant presentenee confinement credit for a misdemeanor DWI. The Court of Appeals noted that statutory authority exists for granting presentence confinement credit for felony convictions, NMSA 1978, § 31-20-12 (1967), but there is no statute addressing presentence confinement credit for misdemeanors in general. As a result,, the Court of Appeals concluded that the existence of such authority is an issue of substantial public interest that should be decided by this Court. See NMSA 1978, § 34-5-14(0(2) (1972) (providing for the certification of appeals from the Court of Appeals to this Court).
II.
{7} In this case, we must determine whether trial courts possess authority to grant presentence confinement credit
1
for inpatient
{8} Our primary goal in interpreting a statute is to give effect to the Legislature’s intent. We look first to the words chosen by the Legislature and the plain meaning of the Legislature’s language. See Whitely v. New Mexico State Personnel Bd.,
{9} Nonetheless, we “must exercise caution in applying the plain meaning rule.” State ex rel. Helman v. Gallegos,
{10} For fourth and subsequent convictions for DWI, the Legislature has provided that “an offender is guilty of a fourth degree felony, as provided in Section 31-18-15 NMSA 1978.” Section 66-8-102(G). Further, the Legislature has provided that “[a] person held in official confinement on suspicion or charges of the commission of a felony shall, upon conviction of that or a lesser included offense, be given credit for the period spent in presentence confinement against any sentence finally imposed for that offense.” Section 31-20-12. “[W]e presume that the [Legislature was aware of other statutes in existence at the time a statute was enacted.” Luboyeski v. Hill,
{11} However, our conclusion that the Legislature intended to provide presentence credit for felony DWI offenders leaves a noticeable void in the statutory scheme. The Legislature expressly has required that credit be given for all offenses other than the second and third, but it has left no indication as to whether credit for the second and third offense should be mandatory, discretionary, or prohibited.
{12} A trial court’s power to sentence is derived exclusively from statute. See State v. Dominguez,
{13} Nonetheless, the judiciary’s role in sentencing criminal defendants is not a purely ministerial task.
Indisputably under our constitutional system the right to try offences against the criminal laws and upon conviction to impose the punishment provided by law is judicial, and it is equally to be conceded that in exerting the powers vested in them on such subject, courts inherently possess ample right to exercise reasonable, that is, judicial, discretion to enable them to wisely exert their authority.
Ex parte United States,
{14} The granting of presentence confinement credit, unlike credit for good time served, as in Aqui or the suspension of a mandatory sentence, as in Mabry and Ex parte United States, does not necessarily interfere with the Legislature’s role in establishing appropriate penalties for crimes. Presentence confinement credit represents a court’s recognition that a defendant, in fact, has satisfied a portion of the penalty mandated by the Legislature. See State v. Trudeau,
{15} As we already indicated, Section 66-8-102 is silent on the issue of presentence credit for second and third offenses but requires preeonvietion credit for jail time with respect to first offenses and, through Section 31-20-12, presentence credit for official confinement with respect to fourth and subsequent offenses. We have noted that the Legislature, by promulgating the 1994 amendments to Section 66-8-102, “sought to increase the punishment for subsequent offenders by conferring fourth-degree-felony status on fourth or subsequent DWI convictions,” rather than changing the nature of the offense of DWI. State v. Ana-ya,
III.
{16} Nevertheless, we conclude that the magistrate court’s reliance on inpatient alcohol treatment as the basis for confinement credit violated Section 66-8-102. In Section 66-8-102, the Legislature has provided for multiple sentencing options. Specifically, for third offenders convicted of aggravated DWI, the Legislature has provided for a mandatory minimum jail term of 90 days. Section 66-8-102(F)(2). This mandatory sentence is not to be suspended, deferred, or taken under advisement. Id. Thus, there is a clear legislative intent to require repeat offenders to spend a specified amount of time in jail. Separately, and in addition to the mandatory jail term, the Legislature has provided that a court may, if necessary, require the offender to attend a court-approved alcohol treatment program. Section 66-8-102(H). The Legislature clearly considered alcohol treatment to be a form of punishment for DWI offenders separate from jail terms. Given this clear legislative intent, we conclude that presentence confinement credit for inpatient alcohol treatment can be applied only to a sentence of alcohol treatment and not to a sentence of jail.
{17} The magistrate court ordered Martinez to attend an alcohol screening program and, based on the recommendations of the screening agency, determined that alcohol treatment was necessary. This punishment is specifically contemplated by Section 66-8-102(H). The magistrate court then applied this treatment as credit for a jail term under Section 66-8-102(F)(2). While the magistrate court generally possessed discretionary authority to award presentence confinement credit, the magistrate court’s substitution of alcohol treatment for jail directly conflicts with the Legislature’s clear intent in Section 66-8-102 and interfered with the Legislature’s function of establishing criminal penalties for DWI.
{18} Our decision that the presentence confinement credit was impermissible applies with equal force to the credit granted for Martinez’s attendance of treatment after the imposition of sentence on May 4, 1995. Again, we believe the Legislature intended to create separate punishment for jail and treatment and to require a specified minimum
{19} Further, with respect to the specific sentence imposed in this case, we conclude that the magistrate court’s attempt to grant credit for postsentence treatment violates an additional legislative directive contained in Section 66-8-102. The magistrate court sentenced Martinez to 364 days in jail and suspended 274 days. As a condition of the suspension, the magistrate court required that Martinez successfully complete the treatment program. The magistrate court then filed a commitment for 90 days jail to coincide with the conclusion of 120 days of treatment at RAP. The treatment and the jail term were clearly separate portions of the same .sentence, to be served consecutively. As a result, the trial court’s grant of credit for treatment between May 4 and June 2 effectively represents a suspension of the jail term, cf. Clah,
{20} Because we conclude that the Legislature created distinct punishments for alcohol treatment and jail, we address neither whether trial courts have discretion, in relation to second and third offenses of DWI, to grant credit for presentence confinement other than jail nor whether any confinement must be preconviction rather than presentence. Compare § 66-8-102(E) (referring to credit for “jail” time served “prior to the conviction”), ivith § 31-20-12 (referring to “presentence” credit for “official confinement”). For similar reasons, it is unnecessary for us to review the district court’s determination that in-patient alcohol treatment is official confinement for purposes of presentence credit, though we recognize that this question may arise under the DWI statute for credit not interfering with a mandatory minimum jail term or under statutory offenses other than DWI. Cf. Clah,
IV.
{21} We conclude that the magistrate court erred by granting credit for 90 days of in-patient alcohol treatment in lieu of the 90 days jail mandated by the Legislature for a third offense aggravated DWI. Thus, we reverse the amended judgment and sentence and remand for imposition of the original sentence in accordance with Section 66-8-102(F)(2).
{22} IT IS SO ORDERED.
Notes
. We note that the record is less than clear as to whether the time Martínez spent in treatment was actually presentence. Martinez entered into a plea agreement on February 14 that was signed by the magistrate judge and the prosecutor. The agreement included, under a section entitled "disposition,” the condition that Martinez attend alcohol treatment. Martinez began attending treatment immediately. Additionally, the plea agreement indicated that a substantial portion of Martinez’s sentence would be suspended for 90 days. Further, it appears that the magistrate court never entered a formal judgment and sentence. Instead, it appears that the court formally sentenced Martinez on either April 4 or May 4, 1995. Because Martinez began treatment immediately after his plea, see Sellers v. Broadwater,
. We note that any legislative prohibition on presentence confinement credit would be subject to constitutional restrictions. Cf. Williams v. Illinois,
