(dissenting). On appeal, Lumbermens argues that the issue of stacking underinsurance benefits was properly preserved for judicial decision and that the judge erred in confirming the $210,000 judgment. I agree.
Relying on the public policy encouraging arbitration as “an expeditious alternative to litigation,” see Plymouth-Carver Regional Sch. Dist. v. J. Farmer & Co., 407 Mass. 1006, 1007 (1990), and rule 4 of the Accident Claims Arbitration Rules of the American Arbitration Association (“AAA”),1 Nancy Malacaria argues that by failing to respond within thirty days *193to her demand for arbitration, Lumbermens waived judicial determination of stacking. While it is true that once in the arbitral arena, arbitral authority is broad and judicial review is narrow, see, e.g., Plymouth-Carver Regional Sch. Dist., supra, the initial determination of whether a dispute is arbitrable at all turns on whether the parties agreed to arbitrate the dispute; a party may not be forced to arbitrate a dispute it has not agreed to arbitrate.
Nancy’s policies included the then standard Massachusetts insurance arbitration provision; one that required Lumbermens and Nancy to arbitrate (1) whether Nancy could recover damages from the accident-causing driver, and (2) the extent of her damages. Moreover, rule 4 requires that" “[w]here [an] insurer moves in court to contest coverage, [arbitration] will be suspended until that issue is determined. Arbitrators may only decide contested issues of coverage where ordered to do so by a court, or where authorized by law, or where both parties so agree in writing.” As there is no evidence that Nancy and Lumbermens agreed in writing to arbitrate coverage or that in denying Lumbermens’ motion to stay arbitration the court “ordered” Lumbermens and Nancy to arbitrate coverage,2 the judge correctly ruled in November, 1989, that the Superior Court had jurisdiction to determine Nancy’s coverage. See, e.g., Royal Indemnity Co. v. Blakely, 372 Mass. 86, 87 n.2 (1977) (“The judge was correct in concluding that the arbitration required by the policy related to ‘questions concerning the insured’s rights against the owner and operator of the uninsured motor vehicle.’ [Citation omitted]. The question of the insurer’s liability under the policy, apart from the insured’s right against the owner and operator of the uninsured vehicle, was for the judge, and the arbitrator’s award purporting to deal with such a question” exceeded his authority).
Moreover, the judge properly ruled that Nancy was limited to $125,000 underinsurance coverage under two of the policies.3 In Cardin v. Royal Ins. Co., 394 Mass. 450 (1985), Jayne Cardin, a passenger in a “Sportabout” car was injured in an accident. At the! time of the accident, the Sportabout carried $25,000 bodily injury coverage and a like amount of *194underinsured coverage. Additionally, Cardin owned a Chevrolet van separately insured for $25,000 underinsurance benefits. Royal Insurance paid the full Sportabout benefits ($50,000) but, relying on the regular use exclusion in the Chevrolet policy, denied underinsurance benefits under that policy. Based on G. L. c. 175, § 113L’s requirement that insurers provide underinsurance coverage, the court ruled the Chevrolet’s $25,000 underinsurance coverage available to Cardin. Id. at 454-455. In Johnson v. Hanover Ins. Co., 400 Mass. 259 (1987), the court clarified its Cardin ruling. In Johnson, Scott Johnson sought to “stack"’ underinsurance benefits beyond G. L. c. 175’s statutory mínimums. The court in denying the purely optional benefits stated: “While the Legislature has set minimum coverage limits of ‘at least’ $10,000 per person per accident, that does not mean that the legislative purpose has been met whenever that person receives the statutory minimum, regardless of her actual damages .... Any benefits provided above those [required by §§ 113L and 113C] are purely optional and thus entirely a matter of contract.” Id. at 264-266. As to policies like the one in the present case, issued before the 1988 amendments to G. L. c. 175, the Johnson rule applies. Thus, Frank Malacaria’s purely optional underinsurance benefits (i.e., those exceeding $25,000) are unavailable to Nancy as they are excluded under the regular use exclusion provision of the policy.
For the reasons stated, I would set aside the judgment entered on November 4, 1993, and direct that the November 27, 1989, summary judgment be reinstated.
Paragraph 4 of rule 4 reads in pertinent part: “The insurer(s) shall have thirty calendar days within which to affirmatively deny coverage or to raise an issue as to applicable policy limits. If no such procedure is initiated, it will be assumed that there is no objection to arbitration and that the claim is denied.”
To the contrary, on the first day of arbitration, Lumbermens expressly preserved coverage for judicial determination.
See note 2 of the majority opinion.