Fairhurst, J.
A no-fault motorist was injured in a car accident with an «reinsured motorist (tortfeasor). She recovered both personal injury protection (PIP) benefits and uninsured motorist (UIM)1 benefits from the same insurance carrier. After arbitration of the UIM claim was complete, the insurance carrier took an offset, in an amount equal to the PIP benefits it previously paid, against the amount it owed in its capacity as UIM carrier. We extend our earlier decisions in Mahler v. Szucs, 135 Wn.2d 398, 957 P.2d 632, 966 P.2d 305 (1998), and Winters v. State Farm Mutual Automobile Insurance Co., 144 Wn.2d 869, 31 P.3d 1164, 63 P.3d 764 (2001), and hold that in order to take a PIP reimbursement offset, the insurance carrier must pay a pro rata share of the legal expenses incurred by the insured to arbitrate the UIM claim.
I. FACTS AND PROCEDURAL HISTORY
In November 1994, Rebecca Hamm was injured in an automobile accident with an uninsured motorist. Hamm qualified as an insured under a policy with State Farm Mutual Automobile Insurance Co. (State Farm) for both PIP benefits and UIM benefits. She received $8,669.71 in PIP benefits from State Farm for medical expenses she incurred as a result of the accident. Rather than pursue her claim against an uninsured motorist, Hamm immediately presented a UIM claim to State Farm. After attempts to settle the UIM claim proved unsuccessful, Hamm pursued arbitration as provided in the State Farm policy. The arbitrator determined that Hamm’s total damages, including medical expenses, were $16,000.00. From the $16,000.00 that State Farm owed to Hamm in its capacity [307]*307as her UIM carrier it offset the amount it previously paid as her PIP carrier, and tendered her a check for the $7,330.29 balance.
The parties disputed the proper amount of the offset, and Hamm eventually brought an action for declaratory relief. The trial court permitted State Farm to offset the total amount of benefits it paid as PIP carrier from the amount of benefits that the arbitrator determined it was obligated to pay as UIM carrier. The trial court, citing Mahler, also required State Farm to pay its pro rata share of the legal expenses (which it set at $6,634.06) that Hamm incurred arbitrating the UIM claim. Because the PIP offset represented approximately 54 percent of the total recovery, State Farm was ordered to pay 54 percent of Hamm’s legal expenses.
State Farm appealed the award of pro rata legal expenses, and the Court of Appeals reversed. Hamm v. State Farm Mut. Auto. Ins. Co., 101 Wn. App. 360, 3 P.3d 761 (2000). We accepted Hamm’s petition for review, and remanded to the Court of Appeals for reconsideration in light of our recent decision in Winters. Hamm v. State Farm Mut. Auto. Ins. Co., 145 Wn.2d 1032, 42 P.3d 1278 (2002). On remand, the Court of Appeals considered Winters, concluded that it did not apply, and declined to amend its earlier opinion. Hamm v. State Farm Mut. Auto. Ins. Co., 115 Wn. App. 773, 60 P.3d 640 (2002). We once again accepted Hamm’s petition for review and now review the Court of Appeals decision not to apply Winters. Hamm v. State Farm Mut. Auto. Ins. Co., 149 Wn.2d 1017, 72 P.3d 762 (2003).
II. ISSUE
Does the pro rata sharing rule for legal expenses articulated in Mahler (recovery from a fully insured tortfeasor) and in Winters (combined recovery from an underinsured tortfeasor and a UIM carrier) apply when the tortfeasor is uninsured and the insured recovers only from a UIM carrier?
[308]*308III. ANALYSIS
A. Background
Two separate and distinct types of insurance coverage are involved in this case—PIP and UIM. PIP coverage generally provides benefits for the immediate costs of an automobile accident, including medical expenses and loss of income. UIM coverage, which functions separately from PIP coverage, covers all damages that the insured would have been entitled to receive from the tortfeasor, including the medical expenses, loss of income, and other damages that are also covered by PIP. See RCW 48.22.030 (UIM), .085 (PIP).
UIM and PIP coverages may overlap with each other and with any potential recovery from the tortfeasor. Although UIM and PIP carriers are permitted to account for any eventual coverage overlap, accounting for overlapping coverage is accomplished differently for UIM carriers than for PIP carriers.
For purposes of UIM coverage, the insurance carrier is said to stand in the shoes of the tortfeasor, and payments made by the UIM carrier are treated as if they were made by the tortfeasor. Britton v. Safeco Ins. Co. of Am., 104 Wn.2d 518, 529, 707 P.2d 125 (1985); Winters, 144 Wn.2d at 880. Accordingly, UIM carriers are entitled to set off the amount of any tortfeasor recovery from the amounts owed to an insured under a UIM policy.2 Hamilton v. Farmers Ins. Co. of Wash., 107 Wn.2d 721, 728, 733 P.2d 213 (1987) (a UIM carrier “always is allowed to credit the full amount of the tortfeasor’s liability coverage against the insured’s damages”). UIM carriers do not need to pay a pro rata portion of the legal expenses the insured incurs to arbitrate a UIM claim in order to take a setoff. Dayton v. Farmers Ins. [309]*309Group, 124 Wn.2d 277, 281, 876 P.2d 896 (1994) (“When a tortfeasor carries insurance, the claimant insured bears his or her own attorney fees in the arbitration proceedings. Thus, when the UIM insurer stands in the shoes of the uninsured tortfeasor, the claimant insured should likewise bear his or her own attorney fees.” (citation omitted)).
In contrast, PIP carriers generally contract for a right to receive reimbursement of PIP benefits if an insured recovers from the tortfeasor, a UIM carrier, or both. While the insured pursues her tortfeasor and UIM claims, the PIP carrier provides benefits to cover the insured’s immediate costs, such as medical expenses. If the insured subsequently recovers the total amount of her damages from another source (the tortfeasor, her UIM carrier, or both), the PIP coverage becomes redundant. Therefore, when the insured receives full recovery, the PIP carrier may seek reimbursement from its insured for the PIP benefits it previously paid. See Winters, 144 Wn.2d at 876 (“the insured must be fully compensated before the insurer may recoup benefits paid”).
Pursuant to Mahler and Winters, if the PIP carrier seeks reimbursement from the funds obtained through the insured’s efforts, the PIP carrier must pay a pro rata share of the insured’s legal expenses. Mahler, 135 Wn.2d at 436; Winters, 144 Wn.2d at 883. As we discuss below, Mahler established this PIP pro rata sharing rule for cases where the tortfeasor is fully insured, and Winters extended the rule to cases where the tortfeasor is ««derinsured. This case presents the issue of PIP pro rata sharing in cases where the tortfeasor is ««.insured.
1. Mahler and the Fully Insured Tortfeasor
In Mahler, the insured was injured by a fully insured tortfeasor. Her medical expenses were initially paid for by her PIP carrier. Subsequently, the insured recovered her full damages, including medical expenses, from the tortfeasor. Once the insured was fully compensated, her PIP carrier sought reimbursement of the PIP benefits it [310]*310paid. We ruled that a PIP carrier seeking reimbursement from the fund created by the insured must pay a pro rata share of the legal expenses the insured incurred in order to recover from the tortfeasor. Mahler, 135 Wn.2d at 407, 436.
As explained in Mahler: “This equitable sharing rule is based on the common fund doctrine, which, as an exception to the American Rule on fees in civil cases, applies to cases where litigants preserve or create a common fund for the benefit of others as well as themselves.” Id. at 426-27. The “common fund” in Mahler consisted of the recovery the insured obtained from the tortfeasor only. From this fund, the insured was compensated and the PIP carrier was reimbursed. Because the PIP carrier reimbursed itself from a fund that the insured created, the PIP carrier was obligated to pay a pro rata share of the legal expenses incurred by the insured to create the fund. Id. at 436.
2. Winters and the Underinsured Tortfeasor
In Winters, the insured, Sarah Winters, was injured by an iinderinsured tortfeasor.3 Her immediate medical expenses were covered by payments from her PIP carrier. Winters then sought recovery from the tortfeasor and recovered the maximum limits of the tortfeasor’s liability coverage. Because the tortfeasor recovery did not fully compensate her, she also pursued a UIM claim.
Unlike the insured in Mahler, Winters was not fully compensated until she recovered from both the tortfeasor and her UIM carrier. Once she was fully compensated, her PIP carrier was able to seek reimbursement for the PIP benefits it paid, subject to its obligation to pay a pro rata share of the legal expenses incurred by Winters in creating the fund. Winters, 144 Wn.2d at 881. As explained in Winters, “[t]hese pooled funds became the common fund from which the PIP insurer was able to recoup payments it had made.” Id. Winters clarified that the pro rata sharing [311]*311rule articulated in Mahler is based on equitable principles, not specific policy language, and applies to PIP reimbursements from UIM recoveries as well as from tortfeasor recoveries. Id. at 878-79, 881.
In cases like Winters, where PIP coverage and UIM coverage are provided by the same insurance carrier, the reimbursement to the PIP carrier typically comes in the form of an offset applied to the UIM obligation. Even though the offset appears to result in a reduction to the UIM obligation, the offset functions as a mechanism to account for the PIP reimbursement and is available only when the same insurance carrier provides both PIP and UIM coverage. In cases where the PIP and UIM carriers are separate companies, the PIP carrier remains entitled to receive actual reimbursement, and the UIM carrier remains obligated to pay the entire amount of the UIM award. In such cases, no opportunity for an offset exists. When the PIP carrier and UIM carrier are the same company, however, an offset against the UIM obligation is an acceptable mechanism to account for the PIP reimbursement rights. Mahler, 135 Wn.2d at 436 (“Provided the insurer recognizes the public policy in Washington of full compensation of insureds and its other duties to insureds by statute, regulation, or common law, the insurer may establish its right to reimbursement and the mechanism for its enforcement by its contract with the insured.”).4
Winters also makes clear that Dayton and Mahler are applied separately to an insurance carrier that provides both UIM and PIP insurance to the same insured. Winters, 144 Wn.2d at 882-83. An insurance carrier that provides both UIM and PIP benefits is not required to pay a pro rata share of legal expenses as UIM carrier in order to take a [312]*312UIM setoff pursuant to Dayton, but is required to pay a pro rata share of legal expenses as PIP carrier in order to take a PIP offset pursuant to Mahler and Winters. Id. The fact that an insurance company providing both PIP and UIM coverage chooses to use an offset from its UIM obligations to account for its PIP reimbursement does not relieve the insurance carrier of its burdens under Mahler and Winters. As the Winters court concluded: “The insured should not be worse off simply because he or she purchased two coverages from the same insurer.” Id. at 882.
B. The Pro Rata Sharing Rule Articulated in Mahler and Winters Applies to Uninsured Tortfeasor Cases
In Mahler, the insured was injured by a fully insured tortfeasor and was fully compensated by the funds recovered from the tortfeasor. In Winters, the insured was injured by an zmderinsured tortfeasor and the recovery included funds from the tortfeasor and the insured’s UIM carrier. In this case, Hamm was injured by an ^reinsured tortfeasor and recovered only from her UIM carrier. As stated above, the question in this case is whether the equitable principle requiring a PIP carrier to share pro rata in the legal expenses of its insured in order to obtain reimbursement of PIP benefits applies when the insured recovers only from her UIM carrier. We hold that it does and reverse the Court of Appeals.
In its order on remand, the Court of Appeals concludes that “Hamm’s UIM carrier received no benefit.” Hamm, 115 Wn. App. at 777 (emphasis added). Focusing on State Farm’s capacity as UIM carrier, the Court of Appeals decided that Hamm is not entitled to reimbursement from her UIM carrier for the legal expenses she incurred to create the UIM arbitration award. Id. at 778. In doing so, the Court of Appeals applied the rule for UIM carrier setoffs from Dayton rather than the rule for PIP carrier offsets from Mahler and Winters.
The Court of Appeals’ conclusions with respect to State Farm’s obligations in its capacity as UIM carrier may be [313]*313correct. As in Winters, however, “[t]he question presented here is totally different: whether or not the PIP carrier should pay a pro rata share of legal expenses for its insured in recovering PIP benefits from an UIM insurer.” Winters, 144 Wn.2d at 882. Although the Court of Appeals notes that “[i]t appears that Hamm is seeking to have State Farm pay a portion of her fees in its capacity as PIP carrier,” it erroneously concludes that “Winters is distinguishable because Hamm’s PIP carrier received no reimbursement,” Hamm, 115 Wn. App. at 778, and “State Farm as UIM carrier received an offset for the PIP payment previously made.” Hamm, 115 Wn. App. at 777 n.l.5
The offset at issue in this case, just as in Winters, is a benefit to the PIP carrier, not the UIM carrier. The Court of Appeals decision to the contrary appears to be based on two erroneous mathematical conclusions. First, the Court of Appeals concludes that applying Winters would put State Farm in a worse position than two separate carriers providing PIP and UIM coverage under the same circumstances. Id. at 777 (“an insurance carrier should not be penalized simply because it provides both UIM coverage [314]*314and medical payment coverage through PIP .. . coverage”). Second, the Court of Appeals mistakenly concludes that “[a]s in Dayton, Hamm would be in a better position for having been injured by an uninsured driver than an insured driver if State Farm were required to pay a share of her fees and costs.” Id. at 779.
As the tables below demonstrate, an insurance carrier providing both UIM and PIP coverage is not penalized when it is required to pay a pro rata share of legal expenses in order to receive its PIP reimbursement. The following tables compare the position of separate PIP and UIM carriers (table A) with State Farm’s position under Winters (table B) and State Farm’s position under the Court of Appeals holding (table C).
Table A
Separate PIP and UIM Carriers, Uninsured Tortfeasor
PIP benefits from insurance company A +$ 8,669.71
UIM award from insurance company B + 16,000.00
Legal expenses to arbitrate UIM claim - 6,634.06
Reimbursement to PIP carrier - 8,669.71
PIP pro rata share of legal expenses6 + 3,582.39
Hamm’s total recovery7 =$12,948.33
Net combination of PIP and UIM payments8 $19,582.39
[315]*315Table B
PIP and UIM from State Farm, [/reinsured Tortfeasor
PIP benefits from State Farm +$ 8,669.71
UIM award from State Farm + 16,000.00
Reimbursement offset - 8,669.71
PIP pro rata share of legal expenses + 3,582.39
Hamm’s total recovery namm s total recovery_ =$12,948.33
State Farm’s net PIP and UIM payments $19,582.39
Table C
PIP and UIM from State Farm, [/reinsured Tortfeasor, No Pro Rata Sharing from PIP (Court of Appeals holding)
PIP benefits from State Farm $ 8,669.71
Legal expenses to arbitrate UIM claim 6,634.06
PIP pro rata share of legal expenses + 0.00
Hamm’s total recovery =$9,365.94
State Farm’s net PIP and UIM payments $16,000.00
By applying the facts of this case and comparing the combined position of separate PIP and UIM carriers to State Farm’s combined position as PIP and UIM carrier, it is clear that State Farm would not be prejudiced by an application of Mahler and Winters. Quite the opposite, by not following Mahler and Winters, the Court of Appeals provides State Farm with a windfall when compared with separate carriers and puts Hamm in a worse position than if she had been covered by separate carriers. The Court of Appeals’ outcome directly conflicts with Winters’ holding that “[t]he insured should not be worse off simply because he or she purchased two coverages from the same insurer.” Winters, 144 Wn.2d at 882.
Our decision that the Court of Appeals incorrectly concluded that Hamm would be in a better position than if she [316]*316had been injured by a fully insured or underinsured driver is demonstrated by comparing Hamm’s position in the following five scenarios: (1) separate PIP and UIM carriers with an «reinsured tortfeasor (table A), (2) State Farm as PIP and UIM carrier with an «reinsured tortfeasor (table B), (3) State Farm as PIP and UIM carrier with an «reinsured tortfeasor and no pro rata sharing of legal expenses by PIP carrier (table C; Court of Appeals holding), (4) State Farm as PIP and UIM carrier with a fully insured tortfeasor (table D; Mahler), and (5) State Farm as PIP and UIM carrier with an wrecZerinsured tortfeasor (table E; Winters).
Table D
PIP and UIM from State Farm, Fully Insured Tortfeasor (Mahler)
Recovery from tortfeasor’s carrier + 16,000.00
Legal expenses to recover from tortfeasor 6,634.06
Reimbursement of PIP payments to State Farm - 8,669.71
Hamm’s total recovery =$12,948.33
Table E
PIP and UIM from State Farm, UrecZerinsured Tortfeasor {Winters)
Recovery from tortfeasor’s carrier + 10,000.00
Setoff for tortfeasor recovery (no pro rata share pursuant to Dayton)_ 10,000.00
Legal expenses to recover from tortfeasor and to arbitrate UIM claim - 6634.06
Reimbusement offset - 8,669.71
[317]*317As tables A through E demonstrate, applying Mahler and Winters would place State Farm in the same position as two separate PIP and UIM carriers, and would place Hamm in the same position she would have been in had two separate carriers provided her insurance. In contrast, failing to apply Mahler and Winters would provide State Farm a windfall, vis-a-vis separate carriers providing the identical coverage, and Hamm would be in a worse position than if she carried insurance from separate carriers.
In addition, application of Mahler and Winters puts Hamm in no better and no worse position than if she had been hit by a fully insured tortfeasor or an underinsured tortfeasor.9 In contrast, under the Court of Appeals decision, Hamm would be in a worse position than if she had been hit by a fully insured or underinsured tortfeasor.
Finally, if we apply Mahler and Winters, State Farm would be in the same position in its capacity as PIP carrier as it would be if (a) it provided only PIP insurance to Hamm, (b) Hamm had been hit by a. fully insured tortfeasor, or (c) Hamm had been hit by an zmderinsured tortfeasor. State Farm’s varying obligations as a carrier under these different factual scenarios would arise only in its capacity as a UIM carrier.10
As in Winters, the issue presented in this case does not depend on State Farm’s role as UIM carrier but rather on “whether or not the PIP carrier should pay a pro rata share of legal expenses for its insured in recovering PIP benefits from an UIM insurer.” Winters, 144 Wn.2d at 882. We hold that State Farm must pay a pro rata share of Hamm’s legal [318]*318expenses in order to take the PIP reimbursement offset, and reaffirm Winters’ holding that an insured should not be worse off simply because she purchased two coverages from the same insurer.
C. State Farm’s Arguments are Unpersuasive
State Farm claims that Hamm received $8,669.71 in PIP benefits and $7,330.29 in UIM benefits. In fact, it is undisputed that the UIM arbitrator awarded plaintiff $16,000.00 in UIM benefits, not $7,330.29. The only difference between State Farm’s position, vis-a-vis two separate carriers providing the same types of coverage, is that State Farm chose to receive its PIP reimbursement through an offset instead of the UIM carrier tendering a check for $16,000.00 and the PIP carrier receiving a check for $8,669.71. As discussed above, the fact that an insurance carrier providing both PIP and UIM coverage can account for the PIP reimbursement by using an offset does not convert the PIP reimbursement into a limitation on UIM coverage. Thus, in effect, Hamm received $16,000.00 from State Farm in its capacity as UIM carrier and no money from State Farm as PIP carrier because, as PIP carrier, State Farm was reimbursed the entire amount of its prior PIP payments. Just as any PIP carrier under Mahler and Winters, State Farm must pay a pro rata share of its insured’s legal expenses in order to receive the PIP reimbursement.
State Farm also suggests that Winters excludes UIM recoveries without a tortfeasor contribution from the definition of a common fund because it states “when a PIP insured creates a common fund from liability payments and UIM benefits, the common fund combines liability proceeds from the tortfeasor’s insurance carrier and UIM proceeds from the insured’s underinsured motorist carrier.” Winters, 144 Wn.2d at 880 (emphasis added). This language, however, is merely descriptive of the factual situation present in Winters, and does not function as a restrictive definition of the necessary elements of a common fund. Neither Winters [319]*319nor Mahler holds that a common fund cannot consist solely of UIM benefits, and we decline to do so now.
Despite suggesting Winters requires the common fund to be a combination of tortfeasor recovery and UIM recovery, State Farm next argues that the money for reimbursement of the PIP carrier must come only from the tortfeasor. See Mahler, 135 Wn.2d at 411 (“ultimate responsibility for a wrong or loss [should be imposed] on the party who, in equity and good conscience, ought to bear it”). State Farm then argues that Winters recognized the insured’s own insurance carrier cannot be the wrongdoer and, therefore, it is the tortfeasor who must ultimately reimburse the PIP carrier for the PIP benefits it paid. See Winters, 144 Wn.2d at 882.
Although we agree with State Farm that the insured’s own insurance carrier is not an actual wrongdoer, State Farm’s argument ignores that “UIM payments are treated as if made by the tortfeasor.” Winters, 144 Wn.2d at 880; see also Finney v. Farmers Ins. Co., 92 Wn.2d 748, 751, 600 P.2d 1272 (1979) (the purpose of UIM coverage is “to allow an injured party to recover those damages which would have been received had the responsible party maintained [sufficient] liability insurance”). We reiterate that UIM payments are treated as if made by the tortfeasor. PIP carriers may be reimbursed when the insured recovers from the tortfeasor, the tortfeasor and a UIM carrier, or a UIM carrier alone.
As a procedural matter, State Farm would have us hold that Hamm could not create a common fund for the benefit of State Farm as her UIM carrier because State Farm, as such, was the adverse party to the UIM proceedings. This argument fails because the common fund benefited State Farm in its capacity as PIP carrier, not as UIM carrier, and PIP carriers are not adverse parties in UIM proceedings.
State Farm also argues that the common fund doctrine cannot apply because State Farm retained its right to sue the uninsured motorist to recover its PIP payments. State Farm could have pursued the uninsured motorist to recover [320]*320its PIP payments but State Farm chose not to do so, perhaps realizing that it would have been as futile for it to try to extract money from an uninsured motorist as it would have been for Hamm to try to do so. Instead, State Farm recovered its PIP payments through reimbursement and must pay the required pro rata share of Hamm’s legal expenses.
As persuasive authority that Hamm’s request for pro rata legal expenses based on the common fund doctrine be denied, State Farm cites to Johnson v. State Farm Mutual Automobile Insurance Co., 323 Ill. App. 3d 376, 752 N.E.2d 449, 256 Ill. Dec. 569 (2001). Johnson, however, was based on an interpretation of specific policy language and the authority of arbitrators to consider various portions of the policy language. See id. at 383. As Winters clarifies, the rule requiring a pro rata sharing of legal expenses is based on equitable principles and not on construction of specific policy language. Winters, 144 Wn.2d at 878-79. Accordingly, we do not find Johnson persuasive.
Finally, State Farm quotes language the legislature omitted from the 1993 PIP statute, RCW 48.22.085, that would have specifically required the type of PIP pro rata sharing of legal expenses later required in Mahler and Winters. Whatever the relevance of the legislature’s unknown intent in omitting this language (State Farm does not cite any legislative history explaining why the quoted language was omitted), both Mahler and Winters were decided after the effective date of the PIP statute. Nothing in the omitted language suggests that the PIP pro rata sharing rule from Mahler or Winters should not be applied in this case.
IV. CONCLUSION
After arbitration of Hamm’s UIM claim was complete, State Farm took an offset, in an amount equal to the PIP benefits it previously paid, against the amount it owed in its capacity as UIM carrier. An insurance company providing both PIP and UIM coverage to the same insured may [321]*321receive its PIP reimbursement, after the insured is fully-compensated, through the use of an offset against its UIM obligations. An insurance company may not, however, style this offset as a reduction of any amount owed under UIM coverage, rather than a PIP reimbursement, in order to avoid paying a pro rata share of the insured’s legal expenses. In order to take the PIP offset, State Farm must pay its pro rata share of the legal expenses Hamm incurred in order to obtain the UIM recovery. The common fund, for purposes of the pro rata sharing rule for legal expenses articulated in Mahler and Winters, may consist of funds from a tortfeasor recovery, a UIM recovery, or a combination of both.
The decision of the Court of Appeals is reversed.
Ireland, Bridge, Chambers, and Owens, JJ., concur.