So walmart is paying the hospitals directly for services provided. This sounds like a good thing assuming they are paying more than insurance would. From the article:
In providing this service at no cost to its enrolled associates, Walmart has worked with these Centers of Excellence health systems to provide exclusive and unique bundled pricing arrangements for these types of procedures. Through Centers of Excellence, Walmart is working with all the health care organizations to collectively share best practices that will allow collaboration around best measures of service and new industry findings in comparison to industry practices.