In trying to both expand Medicare and keep it affordable, Congress has before it one of the toughest tasks it will face this year. It could start with a simple but useful change, introduced by Rep. John Baldacci and several other House members last week, that would offer periodic check-ups to seniors.

While many people might be surprised that the nation’s health coverage system for senior citizens does not already cover physical exams, the proposal, HR 1568, should be included in an overall reform of the Medicare system to ensure that the funding will be available to pay for this and other benefits. The measure is sensibly aimed at preventative care, with the goal of catching illnesses early and treating them while it is still relatively easy to do so.

But the value of these exams isn’t just a chance to do important tests for cholesterol or osteoporosis. The visits give doctors a chance to check on their patients’ diets, ask about exercise or encourage other habits that, with a little professional information, could keep them a lot healthier.

The larger question of Medicare reform, however, isn’t as simple a diagnosis. Early this spring Medicare trustees reported that the insurance system would run short of money once the baby boomers retire, but few people are eager to talk about cutting benefits. Add a prescription-drug benefit and factor in the rapidly rising costs in that area of treatment and a failing system isn’t hard to imagine. New sources of revenue and new measures to keep down costs are inevitable.

But that doesn’t begin to get at some of the issues Congress must address in the near future. Just a few of the issues previous task forces on Medicare have listed include improving reimbursement rates to providers, tying premiums to the incomes of beneficiaries, increasing the age for eligibility and changing Medicare from a defined benefit to a defined contribution plan. These issues have been raised before, but Congress has failed to reach agreement.

It shouldn’t have any trouble finding agreement on encouraging preventative medicine through periodic check-ups. This is a simple change that could end up saving the system money and leaving more re-sources for the other Medicare issues on which Congress has yet to find consensus.