CODING Q&A: Clarity Comes to Modifier 24

What defines an unrelated procedure?


Much has been written about proper and improper use of modifier 25, which allows billing for an exam on the same day as a minor procedure such as an intravitreal injection. Not as much attention is paid, however, to whether an exam is billable within the global surgery period of a procedure, which leads me to modifier 24. It can be confusing, so the following is an attempt to clear up the rules for its use.

Q. Are all exams during the postoperative period following surgery included in the global surgical fee?

A. No. Nearly all patients are directed to return to the surgeon during the postoperative period for an eye exam related to the original surgical procedure. However, there are times when a patient may need to be seen for reasons unrelated to the original procedure. Such a visit may be billed with an evaluation and management (E/M) code (992xx) or an eye code (920xx), with modifier 24 appended.

CPT defines modifier 24 as “Unrelated evaluation and management services by the same physician during a postoperative period.” It goes on to say, “The physician may need to indicate that an evaluation and management service was performed during a postoperative period for a reason(s) unrelated to the original procedure.

This is supported by the Medicare Claims Processing Manual (MCPM) Chapter 12, §40.1B, which states that these visits “… may be paid for separately. … Visits unrelated to the diagnosis for which the surgical procedure is performed, unless the visits occur due to complications of the surgery; …”. This applies to other ophthalmologists in the group as well, because Medicare treats all physicians of the same specialty in a group practice as though they are a single physician; all ophthalmologists, regardless of subspecialty, are considered the same.

Q. What does “unrelated” mean in this context?

A. “Unrelated” means the problem or condition reported by the patient or identified by the surgeon is not connected with the surgery in any way. It is not a complication of the procedure or associated follow-up care. Commonly, “unrelated” refers to the unoperated eye. However, it might also refer to another anatomical part of the operated eye that was not involved in the recent surgery.

Q. Should modifier 24 be used to report a diagnostic test in the global surgery period?

A. Not for Medicare, nor for other payers, unless you are specifically instructed to do so. Diagnostic tests, including diagnostic radiologic procedures, are not included in the global surgery package. For instance, modifier 24 would not be used with OCT testing in the global period. See the examples on the previous page.

Q. Will utilization of modifier 24 trigger a postpayment audit?

A. Possibly. The Office of the Inspector General (OIG) and Medicare contractors closely monitor claims for reimbursement during the global surgery period. Frequent use of modifier 24 could trigger an audit.

Q. What documentation is required in the medical record to support these claims?

A. Several modifiers are used during the global surgery postoperative period:

  • Modifier 25 to identify a significant, separately identifiable exam on the same day as a minor surgical procedure;
  • Modifier 57 to report an exam which resulted in the decision for major surgery;
  • Modifier 58 to report a related procedure during the global period that was staged, more extensive, or postdiagnostic;
  • Modifier 78 to report a related surgery during the global period that required a return to the operating room; and
  • Modifier 79 to report an unrelated surgery during the global period of another procedure. RP

Example 1:

This patient returns with unexplained reduced vision 2 weeks after cataract surgery performed by your partner. She suspects cystoid macular edema (CME), and asks you to examine the patient. You order an OCT, which confirms it. May you claim reimbursement for the eye exam during the postoperative period using modifier 24?


No, because the CME is a complication of cataract surgery and you are within the same practice, although you may be reimbursed for the OCT. If the referral had come from a surgeon in an unrelated practice, your exam would be billable.

Example 2:

Your patient returns with diplopia and distorted vision in the left eye 1 month after vitrectomy for epiretinal membrane surgery in the right eye. You find a new epiretinal membrane in the unoperated left eye, it was not there before. May you claim reimbursement for the eye exam to evaluate the unoperated eye during the postoperative period using modifier 24?


Yes, because the care for the unoperated eye is unrelated to the postoperative care for the operated eye.

Example 3:

Your patient is 1 week post-op from a selective laser trabeculoplasty (SLT) by your partner, a glaucoma specialist. The patient calls and reports new floaters in this eye since yesterday. You examine her and determine she has a peripheral retinal tear in this eye; it was not noted before. You recommend immediate laser. May you claim reimbursement for the eye exam to evaluate the new tear during the postoperative period using modifier 24?


Yes, because the care for the retinal tear eye is unrelated to the postoperative care for the SLT. In addition, if the laser is coded as 67145, and happens today or tomorrow, modifier 57 would also be needed in addition to modifier 24.