Question: How should I code for insertion of an E-string? South Carolina Subscriber Answer: An E-string is a vaginal ring with a whitish core containing a drug reservoir of 2 mg estradiol. It is inserted high into the patient's vagina. Once in place, it begins to release estradiol in a low, continuous dose for 90 days. There is no procedure code for the insertion. You should report the procedure as an E/M service at the appropriate level based on the documentation in the medical record (i.e., history and/or examination and medical decision-making) and code the supply as 99070 (Supplies and materials [except spectacles], provided by the physician over and above those usually included with the office visit or other services rendered [list drugs, trays, supplies, or materials provided). This service may or may not be paid for by a third-party payer. If the procedure is not covered, the E/M service to insert the ring may also not be covered. Always check with your payer. Non-covered services should be billed to the patient.