News that the Senate Democrats were going to allow insurers impose annual or lifetime limits on policy caused quite a stir a few weeks ago. And rightly so. Very few people will ever incur medical bills in the hundreds of thousands or higher. But those that do will be the ones with the worst medical problems--the ones, in other words, who need protection the most.

The White House promised to seek changes, as did liberals on Capitol Hill. It looks like they succeeded. The very first provision of Senate Majority Leader Harry Reid's Manager's Amendment would explicitly prohibit insurers from imposing either annual or lifetime limits.

A group health plan and a health insurance issuer offering group or individual health insurance coverage may not establish—(A) lifetime limits on the dollar value of benefits for any participant or beneficiary; or (B) except as provided in paragraph (2), annual limits on the dollar value of benefits for any participant or beneficiary.

Paragraph (2) makes clear that the regulation goes into effect in 2014, the year the new insurance exchanges would be up and running.) Prior to that time, insurers would still have some leeway to impose limits, although the authority appears to be subject to some government oversight. A senior Senate aide explains:

They can establish limits on non essential benefits. They can establish limits on the dollar value of essential benefits only as the secretary shall determine. So it is likely to be hard and real limits.

By the way, one reason this issue got so much attention was that the left raised a huge ruckus over it. The bloggers at Firedoglake and like-minded sites deserve credit here.

Follow Jonathan Cohn on Twitter: @jcohntnr