City Health Commissioner Donald Schwarz wrote this for the Field Clinic blog on Philly.com and Inquirer.com

Every American needs health insurance. As the glitches on healthcare.gov are repaired, it appears all those who are eligible will be able to enroll.

But when that occurs, what will happen to the overall health of Philadelphians? The Affordable Care Act creates a structure not only to improve access, but to make new investments that seek to prevent chronic illnesses and save billions of dollars.

In other words, it transforms a system focused on sickness into one devoted to wellness.

But the money to do this is in jeopardy (see below).

First, some saving is expected to come from improving Americans' access to preventive services by removing all copayments. More savings were to come from investments in the nation's public health system. These would:

Monitor, prevent, or delay chronic illnesses and ensure those afflicted are identified early and linked to good care.

Fund research into health disparities and the delivery of public health services.

Train more primary-care providers to help treat the influx of patients covered under the act.

Broad preventive efforts are also endorsed, such as more school health centers, healthier corner stores, smoking-cessation resources and media campaigns, and labeling chain restaurant menus to give calorie contents of food.

Many of these initiatives were pioneered in Philadelphia, leading to better eating behaviors and substantial drops in smoking.

These efforts were to have been funded by a large pool called the Prevention and Public Health Fund.

But Congress has whittled away at the fund as it seeks to fill gaps in other parts of the health law. Money from the fund has been used to stop cuts in physician payments mandated by the act (more than one-third of the fund); more was diverted to pay for the development of the online federal exchange (reportedly nearly half the fund for this year).

What remains is not enough to launch and sustain the much-needed prevention work.

So yes, health insurance is critical. But it is also important to realize that healthy people require less health spending (and are happier and more productive). Adequate support for healthier lives is key to making a healthier nation at an affordable cost.

In one ACA-backed project, more than 220 Chinese takeout restaurants in Philadelphia committed to reducing sodium in the 3.2 million meals they serve annually. Restaurant owners and chefs were educated about the health effects of excess sodium consumption, trained in low-sodium cooking techniques, and guided on how to buy low-sodium ingredients.

Six months later, sodium content was down by 20 percent in two popular meals: shrimp and broccoli and chicken lo mein. These efforts can help doctors and patients manage hypertension, which affects nearly 40 percent of city adults.

Trade-offs are a necessary part of the political process, but the long-term success of reform will be measured by the ability to prevent and manage costly illnesses. Public health and prevention strategies are critical to keeping people healthy and making universal care affordable.