Gregoire

More than a decade ago, the Supreme Court acknowledged the growing trend among the states to require health insurers to offer certain benefits as part of every health insurance policy they sell. See Metropolitan Life Ins. Co. v. Massachusetts, 471 U.S. 724, 728-29 , 105 S.Ct. 2380 , 85 L.Ed.2d 728 (1985). In Metropolitan Life, the Court upheld Massachusetts’ once-controversial requirement that insurers offer some limited form of mental-health protection. That trend continues and continues to generate controversy. In this case, we must decide whether Washington’s so-called Alternative Provider Statute is preempted by the Employee Retirement Income Security Act of 1974 (“ERISA”), 29 U.S.C. § 1001 et seq. The Alternative Provider Statute, or “every category of provider” law, requires that health maintenance organizations (“HMOs”) and' health care service contractors (“HCSCs”) cover acupuncture, massage therapy, naturopathy, chiropractic services, and a variety of other “alternative” medical treatments. We conclude that the Washington law is merely the latest variation in an oft-repeated theme, and we reject ERISA preemption.

I.

In 1995, the Washington legislature effected sweeping…