Medical Coding Modifiers: When, How, and Why to Use Them

By: Juan Arredondo and Bri Driggers

Medical coding serves as the backbone of healthcare reimbursement and compliance. Accurate coding ensures that healthcare providers receive appropriate reimbursement for services rendered and adhere to regulatory standards. In the realm of medical coding, one indispensable tool is the modifier

Medical coding modifiers are alphanumeric characters added to procedure codes to provide additional information about a service or procedure. This article explores the definition of modifiers in medical coding, why they are vital, and when and how to employ them effectively.

What Are Modifiers?

Modifiers are two-character codes that convey additional information to payers, auditors, and healthcare providers. These codes are appended to procedure codes to provide more context about a medical service or procedure. Modifiers offer supplementary details about the circumstances surrounding a service or procedure without altering the code itself.

Why Are Modifiers Important?

Modifiers fulfill several critical roles within the domain of medical coding. The first is providing clarification. Though two patients could have received the same type of procedure, the procedures themselves and the circumstances surrounding them could be vastly different. Modifiers add more context than the base procedure codes alone and help paint a more detailed picture of the patient’s encounter. Having an accurate record of what types of services they have received can improve future care and expedite future claims.

Using modifiers can also optimize reimbursement. Often, modifiers tell the payer that the provider performed a more complex service than is usually included with the base code. Just like any other profession, when a healthcare professional does more work, they should be paid accordingly. Modifiers can help secure higher reimbursement for more complicated services when appropriate. Failing to use modifiers correctly may violate payer policies and regulations and lead to denied claims, delaying reimbursement. There may also be more severe consequences, such as audits or financial penalties for your facility. Ensure your team has the proper healthcare compliance training to ensure proper reimbursement and avoid denials. 

When and How to Use Modifiers

Different payers may have different requirements for how to use modifiers when submitting a claim. It is essential to understand each payer’s guidelines for usage and stay informed about any changes to ensure you are using modifiers effectively. Best practices are to thoroughly document which modifiers were applied and why. Any existing documentation in a patient’s medical record must robustly support the necessary use of the modifier.

Let’s delve into common scenarios in which modifiers should be applied:

The American Academy of Professional Coders (AAPC) has outlined several common scenarios in which modifiers should be applied, including:

  • Multiple Procedures: In cases where multiple procedures are performed during a single patient encounter, modifiers like -51 (Multiple Procedures) or -59 (Distinct Procedural Service) may be used to indicate that additional work was involved.
  • Bilateral Procedures: For procedures conducted on both sides of the body during the same session, modifiers like -50 (Bilateral Procedure) or -RT (Right Side) and -LT (Left Side) are utilized to clarify this.
  • Services by Multiple Providers: When different healthcare providers offer services on the same day, modifiers are used to distinguish each provider’s contribution. Modifier -76 (Repeat Procedure by Same Physician) indicates a repeat procedure by the same provider, while -77 (Repeat Procedure by Another Physician) conveys a different provider’s involvement.
  • Unusual Circumstances: In unique scenarios where a procedure demands significantly more work than usual, modifier -22 (Increased Procedural Services) can be employed.

Professional and Technical Components: For procedures with both professional and technical components (e.g., diagnostic tests), modifiers -26 (Professional Component) and -TC (Technical Component) differentiate between the two.




Multiple procedures


Distinct Procedural Service


Bilateral Procedure or RT and LT used to clarify


Repeat procedure by same physician


Repeat procedure by another physician


Unusual: Increased procedural services


For professional and technical components. Used for professional component

Coding Accuracy and Compliance

Every day, insurance companies receive thousands—if not millions—of requests for reimbursement from private practices, hospital systems, and community clinics across the country in a wide range of specialties. There is no possible way for them to review each case in all its complexity. Instead, codes are a much more efficient way to help them process claims and determine who will be getting reimbursed and for how much. While diagnosis and procedure codes are useful on their own, they have their limitations. For one, they don’t convey nuance very well, and insurance companies have very strict guidelines regarding what services are covered for whom and under what conditions. If any part of a claim does not seem to comply with these guidelines at first glance, it is likely to be rejected.

Modifiers help coders be more precise in the claims they submit to payers. If a certain service is covered under specific conditions that would not be evident from just the base code, modifiers can fill in those missing details. They can also let the payer know if the provider completed more or less work than would usually be expected. In these cases, if modifiers were not appended to the code, the provider could be under or overpaid. If the provider is underpaid, you will have to go through a lengthy review process to get the proper compensation. If the provider is overpaid, your practice could be accused of fraud. It is recommended that facilities have a compliance program in place for patient safety, billing of services, and patient privacy. 

For example, modifiers help with unbundling. Some procedures or services are comprised of several components that each have their own associated code. However, when performed together, they are billed under one procedure, which is considered “bundling.” Billing for each component separately is more expensive than billing for the whole procedure together, but it may not be able to represent the full context of the patient’s care. Modifiers help highlight unusual situations in patient care that might deviate from payer expectations and prevent claim denials by helping payers understand why specific code edits were bypassed and unbundled by appending a modifier chosen for a specific situation.

Payer Scrutiny and Audits

If a payer suspects that a claim has been billed inaccurately or is non-compliant with their guidelines, they may want to examine the case more closely. During an audit, they will compare any modifiers used with the patient’s documented medical history. Any modifiers used must align with these records, which is why medical coders need thorough and ongoing training regarding which modifiers are appropriate in which situations. For example, the same payer may cover the same service for some patients but not others based on medical necessity. If a patient has been prescribed a treatment or a procedure that is not always covered, modifiers can help convey information about why this service was medically necessary for this patient. Failure to include the correct modifiers could result in a denied claim. Locate the reasons for your claim denials and what do to about it. 

Using modifiers incorrectly can cause just as many problems for your facility as omitting them altogether. In several cases, the use of modifiers leads to more reimbursement for the provider. Some modifiers used to indicate unusual circumstances or increased complexity may be more likely to trigger audits from private and government-funded payers.

 Payers will also look for inconsistencies or patterns as signs of insurance fraud. Adding modifiers when they are not needed as a tactic to bring in more money than the facility is owed is considered a form of theft and will be caught in a compliance audit. Medical coders must stay informed about what each code means and when it should be applied in addition to each payer’s unique guidelines to help protect the office from unnecessary accusations, audits, and other bureaucratic hiccups that can cost time and money.


Modifiers are indispensable tools in the world of medical coding for conveying the nuanced details of healthcare services and procedures. As we’ve explored, they serve as a bridge between healthcare providers, payers, and auditors and provide clarity and context that can significantly impact reimbursement and compliance. Understanding when and how to use modifiers effectively is not merely a matter of maximizing revenue but also a commitment to maintaining the highest standards of accuracy and adherence to healthcare regulations. Proper utilization of modifiers ensures that healthcare providers are fairly reimbursed for their services while upholding transparency and integrity in healthcare billing and documentation. View our library of medical coding resources

In essence, modifiers are more than mere two-character codes. They are the key to precise and transparent communication in the healthcare industry, ensuring that patients receive the care they need, that healthcare providers are reimbursed fairly, and compliance standards are upheld. As the healthcare landscape evolves, medical coders who master the art of modifiers will continue to play an indispensable role in maintaining the integrity and efficiency of the healthcare system.