By Ben Levine for Kapitall. If you’re an American, you likely know someone or have at least heard of someone who has been to the hospital for something fairly trivial, sat for hours awaiting treatment, and was handed an exorbitant bill. Stories like this are abound. Much of the issue seems to be that patients are being billed for hospital stays that may not have been necessary, and those providing healthcare in various capacities are catching on. As an alternative to the traditional go-to-the-emergency-room model, urgent care clinics are cropping up, offering short waits, short treatment times, and low costs. Essentially, they’re flipping the hospital model of long, high-margin treatments, instead profiting with low margins, high traffic and fast patient turnaround. Pharmacy operators like Walgreen ( WAG), CVS/Caremark ( CVS) and Wal-Mart ( WMT) have opened in-store clinics for convenient treatment at a wider range of hours than going to the doctor’s office, but you probably won’t get to see an actual doctor. Others, on the other hand, are opening urgent care centers, a similar concept wherein patients see an actual doctor. There are now over 10,000 of them across the country, and they’re building some brand recognition. In 2010 healthcare giant Humana ( HUM) purchasedConcentra, the largest urgent care provider at over 300 locations. Health insurer WellPoint ( WLP) has followed suit in opening urgent care centers. Other than Concentra, the largest urgent care chains are U.S HealthWorks, MedExpress, afc, and NextCare. What’s more, even for-profit hospital chains are getting in on the action. As of May, the Tenet Healthcare Corporation ( THC) had opened 23 urgent care centers nationwide. Is urgent care the way of the future for non-critical healthcare? Take a look at the list below and let us know what you think in the comments.Click on the interactive chart to view data over time. 1. CVS Caremark Corporation ( CVS): Operates as a pharmacy services company in the United States. Market cap at $84.93B, most recent closing price at $71.37.