It seems you are talking about two different things. Your question is "Guidelines for billing X-ray with E&M" which is a little different from asking if a written report is required.
There are "usually" no conflicts between CPT for X-Rays (7xxxx) and office E&M (99211-99205) with regard to billing line items (like requiring a modifier).
However, if you are billing separately for the X-Ray, you can't also count it in the E&M level because that would be getting credit 2x.
https://www.ama-assn.org/system/files/cpt-corrections-errata-2021.pdf
"Services Reported Separately Any specifically identifiable procedure or service (ie, identified with a specific CPT code) performed on the date of E/M services may be reported separately.
The ordering and actual performance and/or interpretation of diagnostic tests/studies during a patient encounter are not included in determining the levels of E/M services when the professional interpretation of those tests/studies is reported separately by the physician or other qualified health care professional reporting the E/M service. Tests that do not require separate interpretation (eg, tests that are results only) and are analyzed as part of MDM do not count as an independent interpretation, but may be counted as ordered or reviewed for selecting an MDM level. Physician performance of diagnostic tests/studies for which specific CPT codes are available may be reported separately, in addition to the appropriate E/M code. The physician’s interpretation of the results of diagnostic tests/studies (ie, professional component) with preparation of a separate distinctly identifiable signed written report may also be reported separately, using the appropriate CPT code and, if required, with modifier 26 appended. If a test/study is independently interpreted in order to manage the patient as part of the E/M service, but is not separately reported, it is part of MDM.
You would want to consult and review the radiology billing guidelines and CPT descriptions regarding the required documentation for this. Written reports are required for billing the interpretation with specific parameters. They also require documentation or an order, among other things.
As Orthocoderpgu said, if your practice owns the equipment and it's done in office you wouldn't need to use a TC or 26 because you are billing the global X-Ray. However, there could be state rules and/or CMS rules if a PA or NPP is involved. You may want to check with your internal compliance department or practice manager, etc. This is bigger than just "hey, we started doing this let's bill them."
ACR site usually has info: https://www.acr.org/