Primary Care Coding Alert

Modifiers remain a mystery to many coders who think they know how and when to append them, yet frequently find their claims denied. The problem is so pervasive that improper use of modifiers has been cited as one of the top-10 billing errors by federal, state and private payers and is considered a major fraud, abuse and noncompliance issue.
 
Following are some of the modifiers used most often by family physicians, common mistakes in appending them, and suggestions for proper usage. All the modifiers can be identified with two digits, e.g., -24, as used below, or by adding a 099 prefix, e.g., 09924.

Modifier -21 (prolonged evaluation and management services) indicates that services provided to a patient lasted longer than the usual time for the highest level of E/M service in a category. Medicare does not recognize the code, but Mary Falbo, MBA, CPC, president of Millennium Healthcare Consulting Inc., in Lansdale, Pa., says some payers will provide additional reimbursement for modifier -21 with written documentation.
 
For example, an established patient visits his family physician because of multiple concurrent diseases: osteoarthritis, gout, emphysema, advanced diabetes and a stasis ulcer. After the examination, the physician counsels the patient and his family, resulting in a visit that lasts 65 minutes, 25 minutes longer than the norm for the highest-level E/M (99215) in the category. The coder appends modifier -21 to 99215. Because many payers view modifier -21 as information only (i.e., as a code they recognize but for which they generally do not provide additional reimbursement), Falbo recommends filing on paper instead of electronically and writing a letter explaining the case's complexity and requesting additional reimbursement of a specific amount (usually 25 to 30 percent more).
 
Some coders are also confused about when to use modifier -21 in lieu of the prolonged services codes, 99354-99357. To use the prolonged services codes, the office must document that the doctor spent at least 30 minutes of extra time, but that time does not need to be continuous.
 
"Use modifier -21 when prolonged services are continuous and last less than 30 minutes," Falbo says. "In addition, modifier -21 is used when the face-to-face time or floor/unit service provided is prolonged or otherwise greater than usually required for the highest level of E/M service within a given category."
 
Modifier -21 may be reported with 99205 (office or other outpatient visit for the evaluation and management of a new patient) or 99215 (office or other outpatient visit for the evaluation and management of an established patient), but it would not be reported with any of the other levels of service reported by the physician, e.g., 99204 (office or other outpatient visit for the evaluation and management of a new patient) or 99214 (office or other outpatient visit for the evaluation and management of an established patient). If the physician has not provided the highest level of service in a given category but the service is prolonged, use the prolonged services code(s) if the 30-minute threshold has been met.
 
Many offices find it too time-consuming to file written documentation on modifier -21, but Falbo notes that if enough offices request additional reimbursement, it will eventually show up in audits and may lead to greater acceptance of the modifier.

Modifier -24 (unrelated evaluation and management service) is used when the patient visits the family physician for a problem unrelated to a recent surgical procedure performed by the same doctor.
 
Common errors include using this modifier when the patient returns for surgery-related care during the global period, or when the patient comes in for an unrelated problem after the global period has ended. The modifier should not be used in either of those cases, Falbo says.
 
For example, a patient has a 1.5-centimeter malignant lesion excised from his left arm in the office on Oct. 31. The visit is coded 11602 (excision, malignant lesion, trunk, arms, or legs; lesion diameter 1.1 to 2.0 cm), with a global postoperative period of 10 days. On Nov. 5, the patient returns to the office and is treated for unrelated contact dermatitis. The physician's office uses the appropriate E/M code, e.g., 99213, appended with -24, and diagnosis code 692.9 (contact dermatitis and other eczema; unspecified cause).
 
However, if the reason for the visit on Nov. 5 is a wound check or dressing change related to the Oct. 31 excision, the modifier is not used because the visit is covered under the global package. If the patient comes in with contact dermatitis on the 11th day after surgery, the modifier is not used because the global period has ended.

Modifier -25 (significant, separately identifiable E/M service by the same physician on the same day of the procedure or other service) is used when the physician performs two separate, significant services or procedures at the same visit. Coders often err in appending this modifier by not clearly showing a separately identifiable service performed on the same day as another procedure or service.
 
For example, a man comes to the family physician due to elbow pain. The doctor rules out a fracture via x-ray. Then, determining that the pain is caused by tendinitis, the physician orders an injection for pain relief. The visit is coded with the appropriate E/M level (e.g., 99213) appended by modifier -25, along with 73070 (radiologic examination, elbow; two views) and *20605 (arthrocentesis, aspiration and/or injection; intermediate joint, bursa or ganglion cyst [e.g., temporomandibular, acromioclavicular, wrist, elbow or ankle, olecranon bursa]).
 
The key to securing ethical reimbursement for the service or procedure is to "choose a diagnosis code that supports the medical necessity of the procedure," Falbo says. "Not doing that is the cause of a lot of denials."
 
In this example, 727.09 (synovitis and tenosynovitis; other) supports the medical necessity of 20605 because it pinpoints a specific cause of elbow pain that is responsive to arthrocentesis while 719.42 (pain in joint; upper arm) does not. Code 719.42 is a more general diagnosis that could indicate a sprain, fracture or contusion that would not respond to the procedure.
 
Another example: A patient comes in for a preventive medicine visit and complains of recent wheezing. Use 99395 (periodic comprehensive preventive medicine; 18-39 years) with a diagnosis code of V70.0 (routine general medical examination at a health care facility), then code the appropriate E/M level (such as 99213) for the wheezing problem, append modifier -25, and be sure to link the appropriate diagnosis code, such as 786.07 (wheezing) or 493.20 (chronic obstructive asthma; without mention of status asthmaticus or acute exacerbation or unspecified), to use of the modifier. There must be clear documentation that the asthma was treated separately from the rest of the preventive visit.
 
Note: While different diagnoses can help establish that a procedure is significant and separately identifiable, more than one diagnosis is not required for modifier -25. CPT states in the descriptor of  modifier -25, "The E/M service may be prompted by the symptom or condition for which the procedure and/or services was provided. As such, different diagnoses are not required for reporting of the E/M services on the same date."

When a bilateral procedure is performed at the same operative session, coders have two choices: 1. Use modifier -50 (bilateral procedure) or HCPCS modifiers    -RT (right side) and -LT (left side) or 2. use HCPCS Level II modifiers -RT (right side) and -LT (left side).     

Reimbursement should be similar for both options, but individual payers may have a preference, consultants say. A common mistake in this situation is to code the procedure twice instead of using modifier -50 or -RT and  -LT. For example, an elderly woman with arthritis visits the office due to knee pain. During the visit, the family physician gives the woman injections for pain relief in both knees.
 
In this case, DeVries recommends coding the appropriate E/M (e.g., 99213), 20610 (arthrocentesis, aspiration and/or injection; major joint or bursa [e.g., shoulder, hip, knee joint, subacromial bursa]), and appending modifier -50. Use 20610 just once; modifier -50 indicates that the procedure is bilateral. DeVries says, though, that the office will need to override its normal price structure in billing the procedure to ensure that it receives compensation for treatment of both knees if your practice normally charges $100 for 20610 in one knee, you need to override that and charge $200 for both knees. If the office codes two 20610s instead, DeVries says, "The insurance company interprets that as a duplicate charge" and will typically reject one of the codes.
 
An alternative method, Falbo says, is to code 99213 appended with modifier -25, and to code 20610 twice, appended once with the -RT modifier and once with the -LT modifier to indicate that the procedure was performed on both knees. One advantage to this method is that the office does not need to change its pricing structure, as is necessary with modifier -50.

Family practices often use modifier -51 (multiple procedures) for multiple skin procedures on a patient. Common errors include using this modifier when the same procedure is performed several times. This modifier is used when multiple, different procedures are performed.
  
For example, a patient comes in for several procedures, such as ear-wax removal, excision of a benign lesion and removal of skin tags. Before coding the visit, research which of the procedures has the highest reimbursement. List that procedure first for maximum reimbursement, then append modifier -51 to the other two procedures. Most payers will provide 100 percent reimbursement for the first procedure and 50 percent reimbursement for the following two to five procedures.
 
The good news on this modifier is, "If you don't know what you're doing, many insurers will add it for you automatically," DeVries says.
  
In general, coders should remember that modifiers serve as a flag. Use them to draw payers' attention to unusual situations, but remember they can be a red flag that results in a denial if used incorrectly.