To a generation of Philadelphians, they are known simply as "the free clinics" - city-run health centers where one can get care ranging from pediatrics to dentistry to OB-GYN.

But they may not be free any more.

Even as public-health officials consider massive disruptions in health care - among the options on Mayor Nutter's desk is closing the city nursing home and up to three of the clinics - one change is increasingly likely: Patients without insurance will face fees on a sliding scale at all the centers.

The fees won't be a lot - tentatively a $5 to $20 co-payment per visit - but no one knows the impact on people who are struggling.

"Some will be happy to pay," said Cheryl Bettigole, clinical director of Health Center No. 10, in the Northeast, "but there's no question that it's going to be hard. It's a working-poor population. People are proud. If they can't pay, they might not come."