My wife went to a hospital when she was pregnant for tests 3 years ago. One of the tests done was by a sonogram facility in the hospital and I did not know that they were separate from the hospital. The hospital got paid no problem and I didn't fill out any paperwork for the sonogram place. The sonogram place never billed me for over two years and I wasn't expecting a bill because i didn't know they were separate. Now two years later, collection agency wants me to pay the bill. Hospital said it will try to re-bill insurance and apologizes for not sending me a bill or having my correct address on file. Another year later the collection agency wants payment and it is too late for insurance to pay. If I had known they were separate or got a timely invoice I could have had insurance cover it.