Of course, you may argue that the effort needed for the E&M work for the procedure was above and beyond what is typical for the service, which can be a hard standard to meet. Although the CMS requires a “significant and separately identifiable E&M service” as noted above and a separate diagnosis is not needed, the onus is on you to prove it. It is much easier to have a separate diagnosis that stands on its own, which will probably make an audit less common (unless you do it too often).
Final Thoughts
In summary, document what you do, do what you document, and report what is medically necessary. Keep watch over your EHR to be sure it is not overcoding for you. You do not want to be a ewe!