Modifier 50 Description, Examples, and Usage Guidelines

Left side, right side. One side, two sides. One claim line, separate claim line. Gosh! If your medical coding and billing woes for bilateral surgical procedures are never-ending, then it is time to quit stressing and start grasping. That’s right! We are here to tell you all about the bilateral modifier 50. Report 1 unit of this modifier with the appropriate procedural code to get up to 150% of the standard fee in a single sitting. 

So, let’s uncover the details of modifier 50’s description, real-world applications, and accurate usage guidelines. Your journey to the right billing starts here!  

Modifier 50 – Description

Modifier 50 is typically used with surgical Current Procedural Terminology (CPT) codes to indicate that the procedure was performed on body’s both sides during the same operative session. Hence, it is a bilateral modifier that can help the surgeon collect reimbursement at 150% of the standard fee (100% for the initial procedure and 50% for replicating the procedure on the other side of the body). So, in other words, modifier 50 is also a payment modifier with a significant impact on the net payment. 

The Centers for Medicare and Medicaid Services (CMS) allows using this modifier for increased payment when bilateral procedures are performed. However, you must follow their Physician Fee Schedule Database (MPFSDB) to determine if this modifier should be appended with the chosen procedural code. We will discuss more of this later.  

Modifier 50 – Examples

Knowing when to append modifier 50 makes all the difference when it comes to upping your coding game. Do it right, and you can collect 150% of the cost in one sitting without requesting additional resources. Do it wrong, and you might lose the reimbursement for even the unilateral procedures, as the unnecessary inclusion of modifier 50 will trigger a claim denial. To help you, we have stated a few scenarios below where this modifier is applicable. 

Bilateral Probing of Lacrimal Canaliculi

Blocked tear ducts, a common and harmless condition in infants, can become dangerous for adults, leading to watery eyes and infection. Middle-aged women are more likely to develop blocked tear ducts, also known as dacryostenosis, because of aging and hormonal changes. To remove the obstruction from the drainage system, healthcare providers probe the lacrimal canaliculi. It opens the pathway that connects the eyes and nasal cavity for seamless drainage of tears.  

If a provider unblocks the tear ducts through lacrimal canaliculi probing in both eyes, modifier 50 will be appended with CPT code 68840 to explain the bilateral procedure and collect 150% of the stated charge, which is typically between $140 and $170.  

Bilateral Administration of a Nerve Blocker 

Morton’s neuroma is the non-cancerous yet painful growth of nerve tissues in the foot (typically between the third and fourth toes), causing difficulty in walking and running and persistent pain in the ball of the foot. Bilateral Morton’s neuroma, or the growth of nerve tissues in both feet, is rare. Only around 10-15% of patients are diagnosed with it. However, it needs immediate medical attention to relieve the patient of sharp pain and discomfort. 

Providers inject an anesthetic agent or nerve blocker (corticosteroid) into the area around the digital nerves on the foot’s sole to reduce inflammation and treat Morton’s neuroma. If the procedure is performed bilaterally (on both feet), the modifier 50 will be appended with CPT code 64455. 

Bilateral Removal of Ovaries and/or Fallopian Tubes

This example is an interesting one and goes slightly against the conventional rules of using modifier 50. So, generally speaking, Medicare does not recognize this modifier for procedures performed on midline organs like the uterus, bladder, and esophagus. Moreover, when the CPT code’s descriptor states “one or both” or “unilaterally or bilaterally”, it is assumed to include payment for the procedure on the other side and not in need of this modifier. 

However, with the laparoscopic procedure coded 58661, the situation is a little different. Medicare has assigned this code a bilateral surgical indicator ‘1’. Hence, if the left and right ovaries/fallopian tubes or a combination of both were removed during the same operative session, modifier 50 will be appended with CPT code 58661. Please note that OB/GYNs often advise removing ovaries and fallopian tubes to prevent cancer or treat conditions like ectopic pregnancy. 

Accurate Usage Guidelines for Modifier 50 

So, now that you know which situations mandate the use of modifier 50, let’s consider some of its billing best practices to know for sure when the modifier is applicable and will be accepted by government and private insurance payers. The following guidelines will help you avoid denials related to this modifier.  

Refer to Medicare’s Physician Fee Schedule Database

Medicare has developed a unique billing and coding system for surgical procedures. In its physician fee schedule database (MPFSDB), Medicare lists ‘Bilateral Surgery Indicators’ alongside each CPT code to help the providers ascertain if modifier 50 can be appended or not. 

You can refer to the table below to see if the bilateral surgery indicator quoted in front of the chosen CPT code will guarantee a payment a 150% payment adjustment or not. 

Indicator	Explanation	Use Modifier 50
0	Payment adjustment for bilateral procedures does not apply.	NO
1	Payment adjustment for bilateral procedures applies.	YES
2	Payment adjustment for bilateral procedures does not apply. Already priced as bilateral.	NO
3	Payment adjustment for bilateral procedures does not apply. Bill 1 unit for each side	YES
9	The concept of bilateral procedures does not apply.	NO

Therefore, you can only append this modifier when the bilateral surgery indicator assigned to that CPT code is 1 or 3. Refer to the CMS’s Status Indicators for more guidance. 

While using modifier 50 when the bilateral surgical indicator is 1 is clear-cut, let us explain how this modifier is applicable when the indicator is 3. Generally, radiology procedures or other diagnostic tests will have a bilateral surgery indicator 3. So, Medicare will expect you to report the procedures for each side separately. You will bill 1 unit for the right side with modifier 50 and 1 unit for the left side with the same modifier to indicate that bilateral testing was performed on the same day. Medicare will reimburse you at 100% of the fee schedule for each side. 

Provide Documentation for Bilateral Procedure 

You will have to maintain and submit complete documentation to prove the medical necessity of the procedure performed on both sides during the same operative session. Moreover, the surgical notes must clearly explain how the procedure was performed bilaterally for accurate and timely reimbursement. 

For example, in the case of Morton’s neuroma (nerve tissue growth) on both feet, you can submit X-ray reports to suggest the need for bilateral anesthetic injections (nerve blockers).  

Do Not Use Modifier 50 Under These Conditions

Using modifier 50 will be considered inappropriate when: 

• The code descriptor clearly states that the procedure is “bilateral”. Therefore, the physician fee schedule for the said CPT code includes payment for both sides. 
• The code descriptor clearly states that the procedure is “unilateral”. For example, “Total thyroid lobectomy, unilateral; with or without isthmusectomy”. 
• The procedure was performed on two different areas of the body’s same side. For example, left arm and leg. 
• The procedure was performed on midline organs like the nasal septum, spine, or bladder. Because these procedures are inherently bilateral. 
• The procedure was performed on areas or sites that are not bilateral. For example, thyroid. 
• Medicare’s Bilateral Surgery Indicator for the procedural code is 0, 2, or 9. 

Understand That Commercial Payers May Have Their Own Rules 

While we have stated the dos and don’ts for appending modifier 50 in regard to Medicare billing rules and guidelines, please understand that this may vary across commercial payers. Each insurance payer has its distinct coding guidelines and reimbursement policies. 

So, while they may allow you to bill some procedures bilaterally for increased payment, usage of modifier 50 may be discouraged with other CPT codes. Therefore, we recommend thoroughly reviewing the payer’s contract terms, coding manuals, and billing guidelines before claim creation and submission to avoid payment delays and denials.

Increase the Billed Amount to 150% of the Fees on the Claim 

The American Academy of Professional Coders (AAPC) advises that you should always increase the billed amount to 150% of the standard fees (a rise of 50% from the usual 100% rate) to ensure accurate reimbursement collection. They explain that Medicare does not increase this amount on its own, so you will have to do the math and enter the correct values. 

For example, if the standard fee for the unilateral procedure was $1,000 (charged at 100% of the reimbursement rate), then with the modifier 50 and performed bilaterally, the billed amount on the claim form should be $1,500 (charged at 150% of the reimbursement rate). 

Append Modifier 50 on a Single Claim Line 

When filling out the paper or electronic claim form, enter this modifier on the same claim line as that of the appropriate unilateral CPT code. Moreover, you should report 1 unit in one unit field of that claim line. So, your entry should appear like this ‘20550-50 x1’, where:

• 20550 is the surgery CPT code 
• -50 is the payment modifier 
• x1 is 1 unit of the service

Summary

Here is a quick recap of what we covered in our ultimate guide to appending modifier 50. First, we told you what the modifier indicates and its effect on the reimbursement rate. Second, we discussed some real-world scenarios where it is applicable, such as bilateral removal of ovaries or fallopian tubes, bilateral administration of nerve blockers, and bilateral probing of tear ducts. Lastly, we tried to educate you on the appropriate usage of this modifier and the billing rules you should follow when appending it, like only using it when the bilateral surgery indicators are 1 and 3. 

However, the simplest way to avoid all the fuss and collect accurate reimbursements each time is to outsource medical coding to billing experts like MediBillMD. Their diverse team of AAPC-certified coders excels in procedural coding and modifier usage. 

Frequently Asked Questions