General Motors Corporation (General Motors), as a workers’ compensation self-insurer, compensated Steven Alves for a work-related injury. Because it was Alves’s second injury, General Motors was entitled to reimbursement of some of that compensation, pursuant to G. L. c. 152, § 37. The reviewing board of the Department of Industrial Accidents (board) held that there is no statute of limitations applicable to General Motors’s filing its claim for reimbursement, where Alves’s injury occurred while the 1985 version of the statute was in effect. The Workers’ Compensation Trust Fund (Fund) appealed to the Appeals Court. We granted the Fund’s application for direct appellate review and now affirm the decision of the board.
*172Background and procedure. In order “to encourage the employment of previously injured persons,” Daly v. Commonwealth, 29 Mass. App. Ct. 100, 101-102 (1990), citing G. L. c. 152, § 37, as appearing in St. 1973, c. 855, §§ 2, 5, the Legislature created a fund to provide some reimbursement to workers’ compensation insurers for compensation they pay if such an employee suffers a subsequent injury. The insurer’s eligibility for reimbursement does not begin until it pays the first 104 weeks of compensation. St. 1973, c. 855, § 2. General Laws c. 152, § 37, was further amended in 1985. That amendment increased the amount of reimbursement an insurer could recoup from fifty per cent to seventy-five per cent. St. 1985, c. 572, § 48. It also created the Fund. G. L. c. 152, § 65, as appearing in St. 1985, c. 572, § 55. Money for the Fund comes from an assessment on employers. Id. See Daly v. Commonwealth, supra at 103. Most relevant to our purposes is that the 1985 version of G. L. c. 152, § 37, did not contain a statute of limitations on the filing of reimbursement claims by insurers.
In 1991, § 37 was amended again to add a two-year statute of limitations on the filing of claims for reimbursement for injuries occurring after December 23, 1991. St. 1991, c. 398 §§ 71, 111.1 The Legislature specifically made the amendment to § 37 “substantive,” St. 1991, c. 398, § 106, i.e., the changes were to be applied only prospectively. Austin v. Boston Univ. Hosp., 372 Mass. 654, 657 (1977). See Mills v. Continental Transp. Network, Inc., 44 Mass. App. Ct. 916, 916 (1998), citing G. L. c. 152, § 2A (1991 amendment to G. L. c. 152, § 66, allowing twenty-year statute of limitations on actions against employer, was prospective only).
Steven Alves was employed by General Motors. He suffered a work-related injury within the meaning of G. L. c. 152, § 37, in January, 1987. General Motors began paying reimbursable weekly benefits to Alves on March 10, 1989, ending with a lump-sum payment on March 8, 1991. In April, 2003, General *173Motors filed its claim for reimbursement for its payments beginning in March, 1989. It is uncontested that the 1985 version of § 37 applies to the reimbursement claim.
In July, 2003, at a conference before an administrative judge, held pursuant to G. L. c. 152, § 10A, the Fund was ordered to reimburse General Motors.2 The Fund requested a hearing, which was held before another administrative judge. The Fund argued that a statute of limitations should be read into the 1985 version of § 37 and thus General Motors’s claim was time barred.3 In his written decision of March, 2005, the administrative judge stated that he was bound by the board’s decision in Walsh v. Bertolino Beef Co., 16 Mass. Workers’ Comp. Rep. 151, 153-154 (2002) (Walsh), where the exact issue was raised and rejected by the board.4
The Fund appealed and the board summarily affirmed the judge’s decision, in December, 2005. The Fund appealed to the Appeals Court. G. L. c. 152, § 12 (2).5
Discussion. As the Fund points out, its appeal focuses on “a discrete legal issue concerning the timeliness of the self-insurer’s petition for reimbursement” pursuant to G. L. c. 152, § 37. That “discrete legal issue” involves the validity of the board’s interpretation of the 1985 version of § 37. “The interpretation of a statute by the agency charged with primary responsibility for administering it is entitled to substantial deference.” Gate-ley’s Case, 415 Mass. 397, 399 (1993). The party challenging the board’s decision bears a “heavy” burden of proving that the decision is invalid. Alliance to Protect Nantucket Sound, Inc. v. *174Energy Facilities Siting Bd., 448 Mass. 45, 51 (2006), citing Box Pond Ass’n v. Energy Facilities Siting Bd., 435 Mass. 408, 412 (2001).
The Fund’s argument is premised on the assumption that where a statute does not specify a statute of limitations, courts always borrow one.6 Because the 1985 version of § 37 contains no statute of limitations, it follows, according to the Fund, that the board erred in not borrowing a statute of limitations. The Fund suggests that the most analogous statutes from which to borrow would be either G. L. c. 152, § 41 (four years), or G. L. c. 260, § 3A (three years).7
Although it is true that courts often borrow a statute of limitations when none is supplied, it is not always the case. See State Bd. of Retirement v. Woodward, 446 Mass. 698, 708 (2006) (no *175statute of limitations in G. L. c. 32, § 15 [4], because of Legislature’s clear expression); O’Brien v. Massachusetts Bay Transp. Auth., 405 Mass. 439, 445 (1989) (G. L. c. 260, § 7, tolling statute has unlimited statute of limitations for mentally ill). We also must give substantial deference to the board’s interpretation of G. L. c. 152, unless it is incorrect. Kszepka’s Case, 408 Mass. 843, 846-847 (1990) (board erred in interpreting mandatory language in statute). Moreover, if there is any ambiguity in a statute, “the reviewing board’s interpretation of the statute is entitled to our deference.” McCarty’s Case, 445 Mass. 361, 367 (2005), citing Richards’s Case, 62 Mass. App. Ct. 701, 706 (2004).
As the administrative judge stated in his written decision in this case, the board had already analyzed, in Walsh, the statute of limitations issue raised by the 1985 version of the statute. In Walsh, supra, the board first quoted the administrative judge at length, whose decision pointed out:
“Within its various Sections, the statute contains explicit language limiting the period for which certain benefits shall be paid, limitations on when various notices must be filed by employers and insurers, and also contains limitations on the time within which certain claims for benefits must be filed. Thus, the Legislature included specific limitations where it wanted them to be applied — and conversely, excluded them where it did not want limitations to apply. Only in the most arcane and unlikely circumstances would it be necessary or appropriate to find guidance in analogous statutes than within the Workers’ Compensation Act itself. . . . [Moreover if] the Legislature felt that the Trust Fund would have been prejudiced in some way that required retroactive application of this [1991] limitations period, then it could have enacted a retroactive limitation on petitions, an action it specifically chose not to do here.”
Id. at 152.
In its Walsh appeal, the Fund urged the board to borrow statutes of limitations, particularly G. L. c. 152, § 41, or G. L. c. 260, § 2. Id. at 153-154. The board rejected these arguments for several reasons. It stated that the entire concept of borrowing as it pertains to § 37 had “no bearing on the [Walsh] case.” Id. at 153, citing *176Nantucket v. Beinecke, 379 Mass. 345 (1979). The board relied on the 1991 amendment to § 37 with its explicit prospective application to conclude:
“To apply this statute of limitations to the 1985 version of § 37 would render the Legislature’s prospective characterization of this provision utterly meaningless. Indeed, if the Legislature had intended the new statute of limitations to have retroactive application, ‘it would have been natural for the Legislature to express such an intention,’ as it did for the vast majority of the amendments enacted in 1991. See St. 1991, c. 398, § 107. Where there is such a plain and rational meaning to be applied, we are obliged to apply it, rather than set off on an interpretive quest. See O’Brien v. M.B.T.A., 405 Mass. 439, 443-444 (1989), quoting Commonwealth v. Vickey, 381 Mass. 762, 767 (1980) (‘a basic tenet of statutory construction is to give the words their plain meaning in light of the aim of the Legislature, and when the statute appears not to provide for an eventuality, there is no justification for judicial legislation’).”
Id. at 154.
Moreover, the board explicitly rejected the Fund’s argument that the board should borrow the statute of limitations from G. L. c. 152, § 41, as “meritless,” stating that § 41 covers employee claims for compensation, whereas § 37 covers claims for reimbursement.8 Id. at 154. See Mills v. Continental Transp. Network, Inc., 44 Mass. App. Ct. 916, 916 (1998) (rejecting employee’s request to borrow statute of limitations from § 41 for G. L. c. 152, § 66, where action was one in tort for damages and not workers’ compensation claim). The board also rejected the application of G. L. c. 260, § 2, because it had previously concluded that rights and obligations under § 37 are not contract based. Id. at 154, citing Carmilia v. General Elec., *17715 Mass. Workers’ Comp. Rep. 261, 275 (2001).9 See Ahmed’s Case, 278 Mass. 180, 184 (1932) (workers’ compensation act “creates rights and remedies and procedures all its own, not previously known to the common or statutory law”).
Although it is outside the record in this case, we note that the Fund appealed from the Walsh decision to a single justice of the Appeals Court. The appeal was dismissed because the Fund and the insurer settled.
We will not substitute our judgment for that of an administrative agency if its interpretation of a statute is reasonable. Massachusetts Med. Soc’y v. Commissioner of Ins., 402 Mass. 44, 62 (1988). In its singular focus on its premise that the board erred in Walsh because courts always borrow a statute of limitation where none is indicated, the Fund does not explain how the board’s interpretation of the 1985 version of the statute, including the board’s rejection of borrowing from other statutes, is unreasonable.10 Thus the Fund has not met its heavy burden in this case.
*178It is not unreasonable for the board to conclude that incorporating any statute of limitations into the 1985 version of the statute renders meaningless the prospective nature of the 1991 amendment. “[I]f possible a statute is to be interpreted in harmony with prior enactments to give rise to a consistent body of law.” Hadley v. Amherst, 372 Mass. 46, 51 (1977), citing Everett v. Revere, 344 Mass. 585, 589 (1962) (court’s “interpretation results in a harmonious body of law and explains the subsequent enactments”). Cf. Massachusetts Comm’n Against Discrimination v. Liberty Mut. Ins. Co., 371 Mass. 186, 193-194 (1976) (Legislature’s failure to enact proposed bill amending G. L. c. 151B was “hazardous basis” on which to infer intent of earlier version of statute). It also is not unreasonable for the board to have concluded that, in expressly adding a prospective statute of limitations, the Legislature manifested its intent that *179the 1985 version of the statute have no statute of limitations. Walsh, supra at 153. Cf. Ferguson v. Commissioner of Corps. & Taxation, 316 Mass. 318, 323 (1944) (court will not read discriminatory tax provision into statute where Legislature has not provided “any indication of an intention so to discriminate”). In addition, it is not unreasonable to conclude that the board’s interpretation is in keeping with the purpose of § 37 (facilitating the rehiring of injured workers) by making sure that insurers are reimbursed. Our conclusion is consistent with this “remedial statute,” Walker’s Case, 443 Mass. 157, 161 (2004), where the Legislature anticipated that second injuries caused more serious disabilities. Daly v. Commonwealth, 29 Mass. App. Ct. 100, 102 (1990). See School Comm. of Wellesley v. Labor Relations Comm’n, 376 Mass. 112, 116 (1978), quoting Consolidated Cigar Corp. v. Department of Pub. Health, 372 Mass. 844, 850 (1977) (agency’s interpretation of statute given deference “particularly ‘where [it] must interpret a legislative policy which is only broadly set out in the governing statute’ ”).
The Fund argues that concluding that no statute of limitations applies to the 1985 version of the statute would cause present employers to be assessed unfairly for the costs of reimbursements and benefit those employers who went underassessed in the 1985-1991 period. We do not consider this argument because, as the Fund concedes, there is nothing in the record indicating that this issue was raised before the board and no evidence that it is true.11
We are aware that the board’s interpretation of the statute results in insurers that made payments for injuries that occurred between 1985 and 1991 having an unlimited time to file claims for reimbursement pursuant to § 37, whereas insurers who pay for injuries sustained after 1991 only have two years in which to file for reimbursement. However, the Legislature is presumed *180to intend and understand all the consequences of its actions. Charland v. Muzi Motors, Inc., 417 Mass. 580, 583 (1994). Inconsistencies are for the Legislature to remedy. See Louis’s Case, 424 Mass. 136, 142-143 (1997) (legislative amendments to G. L. c. 152, § 35, created differing benefits for workers injured at different times; inconsistency requires legislative attention). In addition, because we presume that the Legislature is aware of the 2002 decision by the board in Walsh (a presumption not addressed by the dissent) and has not acted to amend the statute, we cannot state that the board’s continual reliance on its holding in Walsh is unreasonable. McCarty’s Case, 445 Mass. 361, 366 (2005) (Legislature presumed to be aware of reviewing board decisions). See Nelson v. Neles Jamesbury, Inc., 16 Mass. Workers’ Comp. Rep. 172, 173 (2002) (quoting analysis in Walsh case to reject Fund’s argument that board should borrow statute of limitations for 1985 version of G. L. c. 152, § 37).12
Conclusion. For the reasons set forth above, the Fund has not met its burden to show that the board’s interpretation of the statute is unreasonable. Accordingly, we affirm the board’s decision.
So ordered.
The 1991 statute of limitations is a “rolling statute of limitations.” Walsh v. Bertolino Beef Co., 16 Mass. Workers’ Comp. Rep. 151, 153 (2002) {Walsh). See St. 1991, c. 398, § 71 (“Any petition for reimbursement . . . shall be filed no later than two years from the date on which the benefit payment for which the reimbursement request is filed was made”).
The parties had stipulated that General Motors had satisfied all other requirements of G. L. c. 152, § 37.
In its brief the Fund argues that this court should borrow a statute of limitations from either G. L. c. 152, § 41 (four years), or G. L. c. 260, § 3A (three years). It is not clear from the record whether the Fund raised these particular statutes in its argument to the board. We assume however, that these issues were raised where, as discussed infra, the board relied on Walsh.
The administrative judge also said that the same issue was present in Oakes’s Case, post 190 (2008), decided today, and the board, as well as a single justice of the Appeals Court, summarily affirmed the administrative judge’s decision that an insurer’s claim for reimbursement was not time barred.
General Laws c. 152, § 12 (2), permits an appeal to the Appeals Court from a decision of the board pursuant to G. L. c. 30A, § 14, and provides that G. L. c. 30A, § 14 (7) (e), does not apply to such an appeal.
The dissent takes issue with the use of the word “always” twice in this opinion to characterize the assumption on which the Fund’s argument for borrowing a statute of limitations is based. Post at 184 n.8. In its brief, in the subheading to the discussion of this issue, the Fund states: “In the absence of an express statute of limitations [in § 37], an analogous statute of limitations must be applied to an insurer’s claim for reimbursement based on the nature or gist of the action” (emphasis added). In addition, the Fund states in it brief, “What no tribunal has done to date, despite clear direction from this [cjourt, is to analyze [the] claims ... to determine what rule of timeliness should apply when stale reimbursement petitions are filed ...” (emphasis added).
Moreover, at oral argument the attorney for the Fund made the unqualified statement that it was a legal error for the board to find no statute of limitations because it was not the law of this court. He also stated, without qualification, that if a statute is silent, the court “will identify and supply” one, because the court has rejected the concept that the absence of a statute of limitations means that none applies; and that the court has said it is “duty bound” to supply a statute of limitations where none exists.
As can been seen, the essence of the Fund’s argument is that a statute of limitations should be supplied here. The semantics over the characterization of the Fund’s argument carries no legal import. As discussed infra, the Fund fails to meet its burden of showing that the board’s interpretation of the statute is unreasonable. Massachusetts Med. Soc’y v. Commissioner of Ins., 402 Mass. 44, 62 (1988).
The Fund does not renew the argument, made before the administrative judge, to borrow the two-year statute of limitations from the 1991 amendment to § 37.
In addition, in a postargument letter, the Fund makes clear that whatever the discussion at oral argument concerning regulations promulgated by the Department of Industrial Accidents, the Fund is not arguing that any regulations bar General Motors’s claim for reimbursement pursuant to G. L. c. 152, § 37.
In its brief the Fund cites Orekoya v. Bank of New England, 14 Mass. Workers’ Comp. Rep. 29, 32 (2000), to support its assertion that G. L. c. 152, § 41, is a valid section from which to borrow a statute of limitations. In Walsh, the board analyzed the reason the Fund’s reliance on the Orekoya case was “unavailing” by stating the reason that borrowing a statute of limitations was appropriate in the Orekoya case but not apt in the Walsh case. Walsh, supra at 154. The Fund does not address the board’s specific analysis of the Orekoya case and thus does not explain how that analysis is unreasonable.
Even though the Walsh decision discussed borrowing from G. L. c. 260, § 2, and here the Fund advocates borrowing from G. L. c. 260, § 3A, the Fund does not explain how the board’s rejection of this particular statute is unreasonable. General Laws c. 260, § 3A, applies to claims against the Commonwealth pursuant to G. L. c. 258, the Massachusetts Torts Claims Act. General Laws c. 152 was designed to replace tort actions. Walker’s Case, 443 Mass. 157, 161 (2004), quoting Neff v. Commissioner of the Dep’t of Indus. Accs., 421 Mass. 70, 75 (1995) (purpose of workers’ compensation act to allow workers, who give up their right to sue employers in tort, to recover for injuries). Although the dissent, post at 189 n.13, states that it would apply the statute of limitations of the Torts Claims Act, the holding in Walker’s Case, supra, illustrates the problem with doing so. Moreover, here, as stated supra, we are not focusing on an employee’s claim for compensation, but the insurer’s claim for reimbursement for monies paid to the employee.
One of the cases on which the Fund relies for its proposition that the board should have borrowed a statute of limitations, Nantucket v. Beinecke, 379 Mass. 345 (1979), was discussed and explicitly rejected in the Walsh decision. The Fund offers no analysis concerning why the board’s rejection of this case was unreasonable. In addition, of the other cases the Fund cites that discuss borrowing statutes of limitations, only State Bd. of Retirement v. Woodward, 446 Mass. 698 (2006), concerns an agency’s interpretation of a statute. In the Woodward case, the court upheld the board of retirement’s interpretation of G. L. c. 32, § 15 (4), because the provision contained clear language supporting its decision that forfeiture proceedings are not subject to any statute of limitations. Id. at 708. Here, the board relied on an explicit provision in the 1991 amendment to § 37 to discern how the Legislature *178intended the board to interpret the 1985 version of the statute. The Fund fails to explain how that interpretation is unreasonable and why it should not be accorded deference. Cf. Locator Servs. Group v. Treasurer & Receiver Gen., 443 Mass. 837, 858-861 (2005) (appeal from judge’s denial of motion for summary judgment; court looked to other sections of relevant statute for statute of limitations as well as to similar statutes of limitations in tort and contract actions against Commonwealth); Oliveira v. Pereira, 414 Mass. 66, 72-73 (1992) (appeal from judge’s decision that claim pursuant to G. L. c. 21E was time barred; statute sounded in tort, where terms such as foreseeability and joint and several liability were used, and therefore, tort statute of limitations applied); Boston v. Gordon, 342 Mass. 586, 590-591 (1961) (appeal from judgment for defendant pursuant to real estate tax collection statute amended to omit statute of limitations; court applied statute of limitations of previous version of statute where reasons for change were obscure).
Moreover, the workers’ compensation cases to which the Fund refers in its postargument letter are distinguishable. Two cases involve statutes of limitations for actual actions filed in court, Pina v. Liberty Mut. Ins. Co., 388 Mass. 1001, 1001-1002 (1983) (employee had three years to commence action against third-party tortfeasor pursuant to G. L. c. 152, § 15); Mills v. Continental Transp. Network, Inc., 44 Mass. App. Ct. 916 (1998), and cases cited (before 1991 amendment to G. L. c. 152, § 66, plaintiff had to maintain action in tort for damages stemming from 1990 injury where employer did not maintain requisite workers’ compensation insurance; employee bound by three-year statute of limitations set forth in G. L. c. 260, § 2A). See L.Y. Na-son, C.W. Koziol, & R.A. Wall, Workers’ Compensation §§ 26.6, 27.1 et seq. (3d ed. 2003). The other case on which the Fund relies, Richards’s Case, 62 Mass. App. Ct. 701, 708 & n.17 (2004), addresses the issue of a statute of limitations applicable to G. L. c. 152, § 11D (3), only in dicta, as the insurer never sought an order pursuant to the statutory provision and thus it was not an issue in the case.
The Fund cites four cases involving § 37 pending in the Appeals Court.
We also note that, according to the plain language of G. L. c. 152, § 65 (3), insurers, such as General Motors, must inform the Fund each year of losses paid under G. L. c. 152 in the previous twelve months. The Fund makes no charge, nor is there any evidence in the record, that General Motors did not fulfil its statutory duty. The Fund does not address how its argument is affected by the incorporation of General Motors data in the annual assessment of employers pursuant to G. L. c. 152, § 65 (3) and (4) (d), as appearing in St. 1985, c. 572, § 55.
Pursuant to G. L. c. 152, § 12A, the insurers request reasonable costs for “attorney’s fees, briefs, and other necessary expenses” in connection with this appeal. The statute mandates that we grant the request. Pursuant to the procedure set forth in Fabre v. Walton, 441 Mass. 9, 10 (2004), counsel should file with the clerk of the Commonwealth a submission detailing and supporting the request for the statutory fees and costs. The submission should be filed within thirty days of the date the rescript issues. The Fund may file a response to the submission within thirty days of the insurers’ filing.