The petitioner, Peggy Denton, appeals a decision of the New Hampshire Compensation Appeals Board (board) denying her request for interest on medical bills, except those she personally paid. We reverse and remand.
The record supports the following facts. In May 1996, the petitioner sustained an injury while working at Surge Industries Corporation. She filed a workers’ compensation claim, which was denied by the employer’s carrier, AIG Claim Services, Inc. (AIG), on the basis that the injury did not arise out of her employment. A department of labor hearing officer denied the claim on the same grounds. The petitioner appealed to the board, which found that her injury did arise out of and in the course of her employment. We affirmed the board’s decision in December 1998. Appeal of Surge Industries Corporation, No. 97-551 (N.H. December 15, 1998). Thereafter, AIG paid the petitioner’s outstanding medical bills, which totaled in excess of $60,000.
In 1999, the petitioner sought an award of interest. The board ordered the payment of “any interest actually accrued on indemnity and *260permanency awards, excluding medical bills, except when paid out of pocket by the claimant.” The board denied the petitioner’s motion for reconsideration. This appeal followed.
The petitioner argues that the interest provision of the Workers’ Compensation Law, RSA 281-A:44,1 (1999), mandates ah award of interest on her contested medical bills. RSA281-A:44,1, provides:
In any dispute over the amount of the benefit payable under this chapter which is appealed to the board or supreme court or both, the employee, if such employee prevails, shall be entitled to reasonable counsel fees and costs as approved by the board or court and interest at the rate of 10 percent per year on that portion of any award the payment of which is contested. The interest shall be computed from the date of injury.
Relying on Appeal of Rainville, 143 N.H. 624 (1999), the petitioner asserts that the “award” contemplated by the statute includes medical bills. She contends that, because she was the prevailing party in a contested award, she is entitled to interest on her medical bills.
We are the final arbiter of legislative intent as expressed in the language of a statute. Appeal of HCA Parkland Medical Ctr., 143 N.H. 92, 94 (1998). In construing a statute, we ascribe the plain and ordinary meaning to words used, considering the statute as a whole and interpreting it consistent with its purpose. Id. At issue here is the Workers’ Compensation Law, which we construe liberally, “resolving all reasonable doubts in statutory construction in favor of the injured employee in order to give the broadest reasonable effect to its remedial purpose.” Rainville, 143 N.H. at 627 (quotation omitted).
The Workers’ Compensation Law does not define “award.” See RSA 281-A:2 (Supp. 2000). Therefore, it is appropriate to examine whether the term has been interpreted by this court. In Rainville, we construed “award” to include medical benefits in the context of RSA 281-A:43, 1(b) (Supp. 1998), the section of the statute pertaining to payment of awards pending appeal. Rainville, 143 N.H. at 628. ‘Words used with plain meaning in one part of a statute are to be given the same meaning in other parts of the statute, unless a contrary intention is clearly shown.” Appeal of Town of Conway, 121 N.H. 372, 373 (1981) (quotation, brackets and ellipses omitted). In examining the statute, we find no indication that the legislature intended the word “award” to have different meanings in sections :43, 1(b) and :44, I. Consistent with our prior interpretation of *261“award” and with the statute’s remedial purpose, we interpret “award” in RSA 281-A:44,1, to include medical benefits.
Surge and AIG assert that the interest provision applies only to medical bills which have been paid by the claimant and not to contested bills which the employer or its carrier have not paid. In support of their position, they rely not on the plain language of the statute, but on New Hampshire Code of Administrative Rules, Lab 208.01(b) (effective July 18,1998).
In workers’ compensation cases, a party’s rights and liabilities, as well as the amount of compensation to which an employee is entitled, are determined by the law in force at the time of the injury. Appeal of Cote, 144 N.H. 126, 128 (1999). Since Lab 208.01(b) was not in force at the time of the claimant’s injury, we need not consider it for the disposition of this case.
Our interpretation of the statute, however, is consistent with New Hampshire Code of Administrative Rules, Lab 510.05, in effect on the date of the petitioner’s injury. Lab 510.05 provided:
If the employee prevails in a contested case appealed to the board or Supreme Court or both, the employee shall be entitled to reasonable counsel fees and interest at the rate of 10% per year on unpaid benefits as per RSA 281-A:44____Interest shall be computed from the date of injury where compensability is in dispute in the first instance and benefits have not been paid____
(Emphasis added.)
Both RSA281-A:44,1, and Lab 510.05 treat all unpaid and contested benefits alike. The claimant is entitled to interest if she prevails. Neither the statute nor the administrative rule limit entitlement to interest on medical bills to those instances where a claimant has actually made an out-of-pocket payment. While it may not seem warranted to award a claimant interest on medical bills she has not paid, it is not for us to fashion such a limitation where the legislature has chosen not to do so.
Surge and AIG argue, however, that our decision in Corson v. Brown Products, Inc., 119 N.H. 20 (1979), precludes the petitioner from receiving interest on her medical bills. We disagree. In Corson, the claimant’s medical bills were paid by the employer’s health insurance carrier until the workers’ compensation decision in his favor. Thereafter, the employer paid the medical bills. Id. at 27. Based upon a virtually identical predecessor interest provision to RSA 281-A:44,1, we denied the employee interest on medical bills because, unlike here, they were not contested; rather they were fully and promptly paid by or through the employer. Our decision in Corson is entirely consistent with our holding today.
*262In this case, the board awarded the petitioner workers’ compensation benefits, including medical benefits. Her substantial medical bills were contested and went unpaid by the employer and its carrier until we affirmed the board’s decision. Consistent with our construction of “award” to include medical benefits and with our interpretation of the interest provision in RSA 281-A:44, I, and the applicable administrative rule enacted under it, we hold that the petitioner is entitled to interest on her medical bills. Accordingly, we reverse the board’s denial of interest and remand for a determination of the interest due.
Reversed and remanded.
Brock, C.J., and Nadeau and Dalianis, JJ., concurred; Duggan, J., dissented.