We were promised profound changes in the way we obtain health insurance in the wake of the passage of health-care reform. 3M's (NYSE: MMM) decision to drop its retiree health insurance plan is an example of how it's likely to play out.

While it does look like the other shoe is falling, the maker of Post-it Notes isn't exactly running away from providing its employees a health benefit. It's simply changing how its employees get their coverage.

Divide and conquer
With retiree access to its health benefit plans starting to phase out in 2013, 3M plans to provide retirees with health reimbursement accounts, allowing them to choose from a variety of plans in the marketplace.

For those who are Medicare-eligible, the HRAs will help them purchase an individual Medicare plan, including privately run ones. For early retirees who aren't old enough for Medicare, their HRAs will go toward purchasing coverage through the exchanges to be created under the new health-care law in 2014.

The biggest change seems to be that instead of tying employees to 3M's company-provided medical plan, they'll buy coverage in the marketplace.

The marketplace of ideas
While that sounds just like how reform advocates want the new health-care law to work, a lot will hinge on what these health insurance exchanges are going to look like. Benefits provider Unum (NYSE: UNM) just put out a helpful guide to explain how the exchanges will operate, but admits that it's based only on known requirements, and points out that the specific rules governing exchanges haven't been written yet.

So why did 3M make the move now? What it's doing is fundamentally different from McDonald's (NYSE: MCD) musings about its mini-med plan.

Instead, 3M's change may be tied to the time frame when the tax deductibility of a federal subsidy provided to companies that cover their retirees' prescription drug expenses expires. Created in 2003 to encourage employers to keep their retiree prescription drug coverage despite the new Medicare prescription drug program, the subsidy will no longer be tax-deductible in 2013. Earlier this year, 3M took an $84 million writedown related to that provision, while AT&T (NYSE: T) wrote down $995 million. Caterpillar (NYSE: CAT) and Deere (NYSE: DE) took earnings hits of $90 million and $130 million, respectively.

Should I stay or should I go?
Since the Obama administration has said that retiree-only plans are largely exempt from the health-care-reform legislation, the drug benefit looks like the catalyst. And even though 3M will no longer be eligible to participate in the Medicare Part D subsidy program as a result of the changes it's making, 3M must believe that its HRA alternative will be cheaper for it in the long run. 3M hasn't said exactly how much it will be contributing to the new HRAs.

These boots are made for walking
Large companies have inexorably changed their relationships with their employees. They've eliminated pensions, switching from defined benefit plans to defined contribution ones, and retiree health benefits have been a popular place for cost-cutting.

A study by Towers Watson suggests more than three-quarters of employers surveyed believe companies will drop coverage as a result of health-care reform, and 50% of them plan to do so themselves. The move by 3M will likely be the first of many more similar announcements to come.