With the outline of a health-care plan announced in Iowa City last week, Barack Obama joins John Edwards and Hillary Clinton in the Democratic chase to remake the nation’s health-care coverage, which is more expensive than comparative coverage elsewhere and leaves 45 million Americans without insurance at all. Mr. Obama is off to a good start.

Most of what is contained in the Obama plan has been seen before, either in Congress or among the many states enacting their own reforms. There’s pay or play – employers either cover their workers or contribute to a public fund – with an exemption for the smallest businesses; guaranteed issue; portability; a government subsidy to cover catastrophic illnesses and a public plan for individuals who cannot obtain coverage (with these two paid for by letting current tax cuts for the upper classes expire). As important as all of these is the plan’s demand for greater transparency of costs.

No one is going to vote for Mr. Obama or Mr. Edwards over their distinction between the former’s plan for universal access and the latter’s universal coverage. What voters should look for is a means for seeing how health-care costs are generated and a mechanism for lowering them without compromising care. Second, they should ensure a plan makes a connection between lower cost and broader coverage, especially early coverage to prevent disease rather than being forced to treat it. Third, a plan must include a substantial section on personal responsibility so that Americans take charge of their own health on issues such as diet and exercise, smoking and excess drinking.

Mr. Obama has each of these areas covered, though his plan needs help in the third area. Something for his campaign to think about: A strong correlation with positive health decisions is education level – more is better, and expectations may have a lot to do with it. An interesting addition to the discussion is his proposal for a National Health Insurance Exchange, designed to create rules and watch over the industry to help individuals looking for private coverage.

Most of the very early presidential debate has been focused on the war, but the discussion is likely to become very different over the next eight or nine months as the consensus for withdrawing troops finally overwhelms the administration. Once that happens, the campaigns will turn toward domestic issues, with health care at the top of the list. Mr. Obama may not have broken ground with his plan – he didn’t need to – but he has made a responsible contribution to the debate.