The State appeals’a decision of the Bennington Superior Court denying extraordinary relief. In its *563decision, the court held that trial courts have the authority, within the confines of the original underlying sentence, to impose split-sentences on probation violators. On appeal, the State argues that the trial court’s sentencing power, once it has found a violation of probation, is limited to the alternatives explicitly laid out in 28 V.S.A § 304 and that those alternatives do not include suspending part of the underlying sentence. We agree and reverse.
Two separate cases with similar procedural histories have been consolidated in this appeal. In State v. Hodgin, the district court imposed an original sentence of nine to eighteen months for operating a vehicle under the influence of intoxicating liquor in violation of 23 V.S.A. § 1201. The court suspended all but thirty days of the sentence and placed defendant on probation. More than two years later, after finding that defendant violated his probation, the district court imposed the underlying sentence, but suspended all but ninety days of the incarceration time and reimposed a term of probation with additional conditions.
In State v. Pratt, pursuant to a plea agreement, defendant pled guilty to violating an abuse prevention order in violation of 13 V.SA § 1030 and engaging in lewd and lascivious conduct with a child in violation of 13 V.S.A. § 2602, and the court sentenced defendant to two one- to three-year terms to be served consecutively. The court suspended both sentences completely and granted probation for each conviction. Three years later, defendant was convicted of failing to report as a sex offender under 13 V.S.A. § 5407. For this third offense, the district court sentenced defendant to a term of sixty days to two years, suspending all but sixty days of the sentence and granting probation for the remainder. Almost two years later, defendant admitted to violating conditions of probation imposed as part of each sentence. For the offense of failure to report as a sex offender, the court maintained the original conditions of probation and left the suspended sentence unmodified. For the two earlier convictions, the court revoked probation and imposed the underlying sentences, but reduced the incarceration time for each offense to one year, to be served concurrently. The remainder of each underlying sentence was suspended, and the court reimposed probation with additional conditions.
Arguing that the new sentences were unlawful, the State sought extraordinary relief in the superior court for resolution of its claims. The superior court denied the petition, and the State now appeals. To be granted extraordinary relief under V.R.A.P. 21(b), the State must show that the district court’s decisions were usurpations of judicial power, clear abuses of discretion, or arbitrary abuses of power. State v. Forte, 154 Vt. 46, 48, 572 A.2d 941, 942 (1990).
The State’s argument is based on 28 V.SA. § 304, which provides the options when a court finds a violation of probation:
(a) If a violation is established by a proceeding conducted in accordance with section 302 of this title, the court may, in its discretion, revoke probation and require the probationer to serve the sentence which was suspended or order that the sentence be served in the community pursuant to the provisions of chapter 6 of this title.
(b) As an alternative to revocation and imposition of sentence as provided in subsection (a) of this section, the court, in its discretion, after a violation has been established, may:
(1) Continue the probationer on the existing sentence; or
*564(2) Effect. . . necessary or desirable changes or enlargements in the conditions of probation; or
(3) Conduct a formal or informal conference with the probationer in order to reemphasize to him the necessity of compliance with the conditions of probation; or
(4) Issue a formal or informal warning to the probationer that further violations may result in revocation of probation by the court.
28 V.S.A § 304. The State claims that once the court decides to revoke probation the plain language of § 304(a) limits the court to imposing “the sentence which was suspended” or imposing a supervised community sentence. The court did neither here, instead exercising an unauthorized third option to fashion a new probationary sentence. The superior court found, and the defendants argue, that the language, when read together with 28 V.S.A § 205(a), impliedly gives the option the sentencing court exercised.
This is a question of statutory construction. The courts have no authority to suspend a sentence or impose a sentence contrary to that authorized by the Legislature. See State v. Pierce, 163 Vt. 192, 196, 657 A.2d 192, 195 (1995). In looking at the legislative authorization, we must use familiar rules of statutory construction. Our principal goal is to effectuate the intent of the Legislature. T. Copeland & Sons v. Kansa General Ins. Co., 171 Vt. 189, 193, 762 A.2d 471, 473 (2000). If the legislative intent is clear from the plain meaning of the language chosen, we enforce the statute according to its terms. State v. LeBlanc, 171 Vt. 88, 91, 759 A.2d 991, 993 (2000). If different sections of statutes were drafted as part of an overall statutory scheme, we must read and construe them together. T. Copeland & Sons, 171 Vt. at 193, 762 A.2d at 473-74.
In State v. Therrien, 140 Vt. 625, 627-28, 442 A.2d 1299, 1301 (1982), we described the options available under § 304 as “to revoke probation and require the original sentence to be served, continue probation, or alter the conditions of probation.” See also State v. Draper, 167 Vt. 636, 637, 712 A.2d 894, 894-95 (1998) (mem.) (same). This list of options comports with the plain meaning of the language used by the Legislature. The options do not include the one attempted to be exercised here, revocation of probation and imposition of a different sentence from that imposed originally.
We do not reach a different conclusion when we read § 304 together with 28 V.S.A § 205(a). Section 205(a) provides that “[a]fter passing sentence, a court may suspend all or part of the sentence” and place the defendant on probation. We held in Therrien that the sentence is “passed” when it is originally imposed and suspended, not when the court requires that it be served upon revocation of probation. 140 Vt. at 627, 442 A.2d at 1300-01. Except where there is a specific legislative authorization, a court cannot modify a sentence once the defendant has commenced to serve it. See State v. Harbaugh, 132 Vt. 569, 579-80, 326 A.2d 821, 827 (1974). The only authority is in 13 V.S.A. § 7042, and that authority expires ninety days after the sentence is imposed or ninety days after the judgment of conviction is final, whichever is later. See Therrien, 140 Vt. at 627, 442 A.2d at 1300; see also State v. Priest, 170 Vt. 576, 577, 743 A.2d 1072, 1073 (1999) (mem.) (on revocation of probation, “court’s authority to alter a sentence, whether to increase or reduce it, is limited by 13 V.S.A § 7042(a), which allows alteration only within ninety days of the imposition of the original sentence.”) (emphasis added); State v. Draper, 167 Vt. at 637, 712 A.2d at 895. *565The authority has expired in the cases before us. As a result, the sentencing court no longer had power under § 205 to suspend an additional part of the underlying sentence when it revoked probation.
The superior court held that in enacting § 304, and explicitly providing for five options when the State proves a violation of probation conditions, the Legislature’s intent must have been to allow further suspension of parts of the underlying sentence to allow the sentence to fit the offender at the time the violation of probation is shown. It labeled any other conclusion as “absurd.” We agree that allowing broad flexibility in sentencing is a preferable policy, and the sentences before us are reasonable, but we can find no indication that the Legislature intended to allow them. In fact, § 304(a) explicitly authorizes the court to impose a supervised community sentence, which is an alternative sentence to the original sentence that allows part of the sentence time to be served in the community. See 28 V.S.A. § 352. This provision shows that the Legislature knew that to provide an alternative to the underlying sentence it must explicitly authorize it, and that the Legislature considered at least one alternative. Because § 304 provides an explicit alternative to imposition of the underlying sentence, we cannot conclude that the failure to provide for the alternative the sentencing court used here was an oversight. See In re Stowe Club Highlands, 164 Vt. 272, 280-81, 668 A.2d 1271, 1277 (1995).
We cannot label the Legislature’s limit absurd or irrational. With approval of the corrections department, the court could accomplish much of its purposes with a supervised community sentence pursuant to § 352. Moreover, in the cases before us, some of the actions that violated the probation conditions were crimes. The court could refuse to revoke probation, leaving the prosecutor to commence new criminal cases to obtain additional incarceration. The court would face no restrictions in sentencing for the new crimes.
We also cannot accept that we should deviate from the plain language of § 304(a) because, as defendants point out, § 304(b) was taken in large part from an external source, American Bar Association, Standards for Criminal Justice: Probation § 5.1(b) (Approved Draft 1970). Defendants argue that in cases where the Legislature attempts to integrate provisions of a model act with different locally-drafted provisions, we must conclude that the language of the model act is used for the same purpose as in the model act. See In re Margaret Susan P., 169 Vt. 252, 264, 733 A.2d 38, 47 (1999); State v. Papazoni, 159 Vt. 578, 582, 622 A.2d 501, 503 (1993). Defendants point out that the ABA standards allow the court full flexibility on revocation of probation in fashioning an incarceration sentence. We are not construing the model act language as in Margaret Susan P. and Papazoni; the fact that a section we are not construing, § 304(b), is taken from a model act sheds no light on the proper construction of § 304(a).
The superior court should have granted extraordinary relief to strike the sentences imposed on defendants after the district court revoked probation, and to require the district court to chose a remedy authorized by 28 V.S.A. § 304.
Reversed.