I have used the CoaguChek device. Easy to use and convenient. I use it to monitor my Mom's INR. I got the idea to use it in the office. I obtained the necessary CLIA waver and started using in the office. A month or so later I got a letter from the State if NJ informing me that despite the CLIA waver, NJ required a lab license and proficiency testing and that I would be fined if I continued without the license even if I did not charge for the test. So, check with your state before you make any assumptions.