AP Photo

Health insurers in many states have been seeking double-digit premium increases from people who buy their own policies directly from the companies rather than obtaining group coverage at work. In states where regulators have the power to curb excessive rate hikes, the increases are often rejected or negotiated down. In those where the regulatory laws are weak not much can be done beyond jawboning.

This hodgepodge of controls over premiums needs to be backstopped by a national law that would allow the federal government to block unjustified rate increases where state officials lack the authority to do so. Attempts to include such powers in the newly enacted health care reform law failed. And while the reform law does have provisions that should help restrain premiums, they lack...