In this case, we consider whether G. L. c. 276, § 52A, authorizes a judge in the Superior Court to order the “removal” (transfer) of pretrial detainees from a county jail to a State correctional facility. We conclude that it does not.

Background. On August 16, 2005, the district attorney for the middle district (Worcester) submitted a written request to a judge in the Superior Court seeking an ex parte order that fifty-one pretrial detainees, who were being held at the Worcester County jail or house of correction, be removed by the Commissioner of Correction (commissioner) to await trial at a State correctional institution pursuant to G. L. c. 276, § 52A.^[2] The request was silent as to any factual basis that might support it,[*124] and was unaccompanied by affidavit. Without notifying the commissioner, the judge endorsed the request and signed the order prepared by the district attorney. The order was then transmitted by facsimile to the commissioner by the sheriff of Worcester County. The commissioner filed a motion to vacate the order, which was denied.

In his memorandum denying the commissioner’s motion, the judge wrote that the issue had come before him “as a purely administrative matter” and that he had allowed the district attorney’s request because he interpreted G. L. c. 276, § 52A, as authorizing him to do so, and that “even without an evidentiary hearing this Court is well aware . . . that ... at least in Worcester County . . . there are simply not a sufficient number of beds to provide for the basic needs of those who need to be incarcerated.” The commissioner timely moved for reconsideration, which was denied. The commissioner then filed a petition in the Supreme Judicial Court for Suffolk County pursuant to G. L. c. 211, § 3, seeking relief from the order. On November 16, a single justice reserved and reported the case without decision to the full court.

Discussion. We interpret a statute according to the intent of the Legislature. Commonwealth v. Galvin, 388 Mass. 326, 328 (1983). “[T]he primary source of insight into the intent of the Legislature is the language of the statute,” International Fid. Ins. Co. v. Wilson, 387 Mass. 841, 853 (1983), and that is our starting point. Simon v. State Examiners of Electricians, 395 Mass. 238, 242 (1985). Statutory language should be given effect consistent with its plain meaning. Where, as here, that language is clear and unambiguous, it is conclusive as to the intent of the Legislature. Commonwealth v. Clerk-Magistrate of the W. Roxbury Div. of the Dist. Court Dep’t, 439 Mass. 352, 355-356 (2003).

[*125] General Laws c. 276, § 52A, provides for the transfer of pretrial detainees from the county jails in which they are ordinarily held awaiting trial. In separate sentences, the statute authorizes two different types of detainee transfers. The first is a transfer from one county jail to another. The second is the transfer from a county jail to a State correctional facility. To facilitate both, the commissioner is authorized to be the removing agent, responsible for transporting the detainees to the receiving facility and, when requested by the district attorney, for returning them to the jail where they were originally awaiting trial.^[3]

The transfer of a detainee from one jail to another is authorized in the first sentence of the statute. It provides that such a transfer “may” be made “with the approval of the district attorney,” and “shall” be made “by order of a justice of the superior court.” The transfer of a detainee from a jail to a State correctional facility is authorized in the next sentence, which similarly provides that it “may” be made “with the approval of the district attorney,” but makes no provision for transfers to be made by order of a judge of the Superior Court. The second sentence further provides that only pretrial detainees who have previously been incarcerated in a correctional institution for a felony may be transferred from a jail to a State correctional institution to await trial.

As to the first type of transfer, it is apparent that the statute vests discretion in the district attorney to approve (or disapprove) whatever arrangements may be made by the various sheriffs to accept such transfers, and vests the authority in the Superior Court to order them when that may be necessary, whether or not sheriffs so agree. As to the second type of transfer, similar discretion lies with the district attorney, but no authority is provided to the Superior Court to direct such transfers should the commissioner decline to accept them. The absence of parallel language in the second sentence of the statute as to the authority of the Superior Court cannot be ignored.[*126] “[W]here the legislature has carefully employed a term in one place and excluded it in another, it should not be implied where excluded.” Commonwealth v. Gagnon, 439 Mass. 826, 833 (2003), quoting 2A N.J. Singer, Sutherland Statutory Construetian § 46.06, at 194 (6th ed. rev. 2000). We do not read into the statute a provision which the Legislature did not see fit to put there, nor add words that the Legislature had an option to, but chose not to include. General Elec. Co. v. Department of Envt’l Protection, 429 Mass. 798, 803 (1999).

The Superior Court judge affords great weight to the prefatory phrase of the second sentence, “In addition,” concluding that those words were intended to mean that the authority given to the Superior Court in the first sentence carries over to the second. This interpretation is not, however, consistent with the sentence structure of the statutory language. The prefatory phrase simply indicates that there is another type of removal for “[pjersons held in jail for trial” (“In addition, such persons . . . may ... be removed ... to a correctional institution of the commonwealth . . .”). The repetition of the language requiring the “approval of the district attorney” in the second sentence, but the failure similarly to provide any authority for the Superior Court, proves fatal to the judge’s logic.^[4]

Our interpretation of the statute, which is consistent with its[*127] language, does not lead to an illogical result. Unlike the county jails, the State correction system is not set up to accommodate the special needs of pretrial detainees. See G. L. c. 276, § 42 (prisoners not released on bail “shall be committed to jail”).^[5] The Legislature could reasonably have concluded that the commissioner is in the best position to know whether and which State facilities have bed space, whether those facilities include an appropriate level of security, and whether such facilities are geographically suitable to accept any particular detainee. It is not illogical in these circumstances to vest the commissioner with the discretionary authority to accept detainee transfers to the State correctional system. Nor is it illogical for the Legislature to have concluded that to authorize Superior Court judges sitting in every county to decide how many pretrial detainees will be transferred from county jails to State correctional institutions to await trial could wreak havoc on the management of that complex system. The case is remanded to the single justice where an order is to enter vacating the removal order.

So ordered.