Modifier 24, revisited

Cracking the Code

Alexander Miller

Dr. Miller, who is in private practice in Yorba Linda, California, represents the American Academy of Dermatology on the AMA-CPT Advisory Committee.

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A patient comes in for an evaluation of an itchy neck rash 30 days after you excised a right neck squamous cell carcinoma and repaired the defect with an advancement flap. You diagnose a contact dermatitis to nickel jewelry and treat it with a topical steroid and an admonition to avoid contact with nickel-containing products. Is the visit billable during the 90-day surgical global period for an adjacent transfer/rearrangement surgery, and if so, how should the bill be presented to the insurer?

The Current Procedure Manual (CPT®) specifies that modifier 24 may be appended to an appropriate evaluation and management (E/M) service code (99212-99215) when E/M services unrelated to that of a prior surgical procedure are provided during the global period by the same physician or qualified health care professional who did the surgery. Since the global period is 90 days for a flap procedure, a modifier 24 is necessary for pointing out to the insurer that a distinct E/M service was done. Why is that? It is because 10- and 90-day global periods are valued to include at least one (or more) postoperative E/M visit during 10 or 90 postoperative days. Appending a modifier distinguishes the provided service as not being related to the prior procedure. Particularly for 90-day global period procedures, it is possible to see a patient for an unrelated problem during those 90 days and then to forget to append the 24 modifier simply because substantial time had elapsed since the original surgery. That, of course, will result in a payment denial and (at least for Medicare) an explanatory note stating that the payment for the visit was included in a previous procedural charge.

Chart documentation must support the impression that E/M services provided during a global period were not related to the original surgical procedure or medical complications from that procedure. Listing an ICD-9 or ICD-10 diagnosis code distinct from that of the original surgical procedure will typically validate the legitimacy of an E/M billing.

Appropriate inclusion of a 24 modifier does not guarantee payment or the durability of the payment. Medicare Administrative Contractors typically follow clear-cut guidelines and will reimburse justly based upon modifier 24 guidelines and definition. Other insurers may or may not follow the same approach. Some may deny a proper E/M claim, and others may hold claim adjudication, request supporting chart documentation, and then pay (or not pay) the claim. Keep in mind that frequent, statistical outlier use of the 24 modifier may prompt a focused audit of multiple patient charts. In all cases, clear and uncontestable chart documentation supporting the distinctiveness of E/M services provided during the global surgical period should help one’s cause. Despite all of one’s best billing efforts, insurers may deny some legitimate claims. It is essential to have billers who will identify inappropriate payment denials, appeal them properly, and then track them to their ultimate resolution.[pagebreak]

Example 1. You excise a squamous cell carcinoma from the right temple of an elderly man with two stages of Mohs surgery and allow for healing by secondary intention. Nine days later the patient returns complaining of right forehead and scalp pain along with an onset of small vesicles along the painful area. You diagnose herpes zoster and bill for the visit as CPT 99212-24, specifying that you provided an E/M service distinct from the prior surgery.

Answer: Incorrect. The 24 modifier is not necessary, as Mohs surgery, CPT 17311-17315, has a zero-day global period. When the global period is zero, all appropriate care provided on the day following the procedure and beyond is billable without a modifier.

Example 2. A patient who had a benign cyst excised five days prior by an outside dermatologist comes in to see you for a possible wound infection. You indeed diagnose a wound infection and treat it accordingly. You bill CPT 99202 for the E/M visit.

Answer: Correct. As the patient is new to your practice, you bill for the visit as you would for any new patient. Modifier 24 is not needed.

Example 3. A physician in your dermatology group practice does a flap repair on a Medicare patient and leaves for a conference two days later, subsequent to which you evaluate a postoperative wound infection and start the patient on antibiotic therapy. As the patient is new to you, you bill an appropriate E/M code with a 24 modifier to show that care was provided during the postoperative period.

Answer: Incorrect. Medicare guidelines state that physicians of the same specialty within a group practice must bill as one and the same physician. Also, complications during a global period, including infection, are treated as part of the surgical package and are not separately reimbursable. Consequently, the wound infection treatment visit is not separately billable, with or without a 24 modifier.

Example 4. The elderly patient whom you started on antibiotic treatment for a flap repair site wound infection returns one week later, well within the 90-day global period, complaining of an intensely itchy, spreading, diffuse rash. You note a bilaterally symmetrical urticaria-like eruption with some focal vesiculation on the extremities and abdomen. Is it a drug eruption or is it bullous pemphigoid? You do an appropriate evaluation and decide to biopsy an urticarial patch-based vesicle. You then bill for the office visit as CPT 99213-24 and for the biopsy as CPT 11100-79.

Answer: Incorrect. The E/M done is for a problem not directly related to the surgery. Consequently, a 24 modifier is indicated. The biopsy was done during a global period of the prior surgery, so a 79 modifier is appended. The E/M service that resulted in a decision to perform the biopsy included a history and a complete skin examination constituting substantial E/M work. Therefore, a 25 modifier is needed to specify that a separately identifiable E/M service was done at the same time as a procedure was performed.

The correct coding is: 99213-24-25 for the E/M service and 11100-79 for the biopsy.

Example 5. On the twelfth day following an excision of a clinically atypical nevus a patient returns for suture removal complaining of an itchy, pink, scaly scalp. You diagnose and treat seborrheic dermatitis. You bill CPT 99212-24 for the visit.

Answer: Incorrect. An excision with or without an intermediate or complex repair has a 10-day global period. The 10 days are counted starting on the day after the procedure. As 12 days are beyond the 10-day follow-up period, no modifier is required for the billing. Inappropriate use of any modifier may or may not result in a claim rejection. It does, however, generate a utilization statistic for that modifier. Inflated utilization statistics generated by inappropriately used modifiers can result in subsequent unwanted claims scrutiny.