Agencies claiming compliance on insurance scheme (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

MEDIA (agencies? Perhaps as the plural of medium = agency = the means by which something is achieved?) containing (claiming) C (which can stand for “compliance” in various abbreviations, but I don’t think it’s something many of us would use), then RE (on = on the subject of). This all seems pretty obscure to me, unless there’s a simpler explanation that I’ve missed. The US federal health insurance scheme, or similar schemes in Australia and Canada.