Are you ready to file your claim? Or have you forgotten an important modifier? Choosing the correct modifier can make all the difference, especially if you have performed several procedures on the same patient and within the same visit. Modifiers offer additional information to payers about a service or procedure. The best part is that they don’t change the definition of a CPT code.
Both modifiers 51 and 59 can help you justify the reason for billing multiple procedures for the same patient. But which one is more suitable for your situation? Many healthcare providers face claim denials or underpayments because they confuse modifier 51 with 59 or vice versa. Let’s discover their main differences so you can use them accurately.
What is Modifier 51?
Modifier 51 in medical coding defines multiple procedures or surgical interventions. In simple terms, this modifier informs payers that a healthcare provider performed two or more surgical interventions within the same session.
However, these procedures are billed on two separate claims. Moreover, they typically exclude evaluation and management (E/M), physical medicine and rehabilitation services, or supply provisions, including vaccines.
The most important thing about using modifier 51? List all the procedures in proper order. This is important because insurance companies only offer complete reimbursement for the first surgery and apply a multiple procedure payment reduction (MPPR) to subsequent operations.
Therefore, list the most complicated (highest paying) procedure first on your claim and apply modifier 51 to the additional operations. Medicare has some rules regarding this modifier:
- You cannot use modifier 51 with add-on codes (Appendix D in CPT’s manual)
- Don’t use it when different physicians perform different and unrelated surgeries.
In the past, healthcare providers faced claim denials because they applied this two-digit code to all the procedures performed on the same patient during a single session. Want to know why insurance companies rejected those claims? The National Correct Coding Initiative (NCCI) edits by CMS.
The National Correct Coding Initiative (NCCI)
Tired of improper coding and billing practices, the Centers for Medicare and Medicaid Services (CMS) introduced the National Correct Coding Initiative (NCCI) in 1996. The primary goal of this program was to control the improper unbundling of Medicare’s Part B procedures or services, which usually resulted in inflated charges.
In simple words, CMS established several coding edits, including Procedure-to-Procedure (PTP) edits, through NCCI to reduce inappropriate payments in case of incorrect coding combinations.
Procedure-to-Procedure (PTP) Edits
These automated edits in NCCI prevent improper payment by specifying pairs of HCPCS/CPT that should not be paired for the same session. In other words, these edits are essential for distinguishing which procedures are a part of primary service and which are distinct enough to be billed separately.
So how does this work? And what effect does it have on modifiers 51 and 59? Each PTP edit has an associated Correct Coding Modifier Indicator (CCMI) – 1, 0 or 9.
- CCMI of 0: You cannot use an NCCI PTP-associated modifier for the reported pair of codes.
- CCMI of 1: You can use NCCI PTP-associated modifiers for the reported pair of codes, but only under appropriate circumstances.
- A CCMI of 9: There is no specific rule regarding the use of NCCI PTP-associated modifiers for the specific code pairs.
Simply put, a CCMI of 0 identifies codes that should never be reported together for the same patient and session. CCMI of 1 specifies the codes that can be bundled under specific conditions.
Modifier 51 under NCCI
With the introduction of NCCI, the use of modifier 51 has significantly reduced. PTP edits now specify when procedures should be bundled or unbundled. Hence, this modifier is only applied where there is no NCCI restriction.
What is Modifier 59?
Modifier 59 in medical billing is slightly different from modifier 51. It indicates a distinct or a separate procedure. In simple words, billing experts use this modifier to notify payers that the provided service, excluding E/M, is unrelated to other procedures or services performed on the same day and should be reimbursed completely.
Although these services are not usually reported together, modifier 59 clarifies their necessity in that particular situation. Insurance companies require proper documentation with this modifier, including the medical necessity of the performed operation and anatomic site.
In short, you can use modifier 59 to report:
- Different sessions or patient encounters within the same day
- Distinct procedures from the primary operation
- Different areas of operation (anatomic site)
- Separate incision, injury, or excision
Remember that you should only apply modifier 59 when no other code explains the situation. You can use this modifier when a PTP edits’ CCMI is 1 for a coding pair.
Modifiers 51 vs 59 – Key Differences
Modifiers 51 and 59 have 4 key differences.
Purpose
Modifier 51 specifies that multiple procedures, excluding E/M, were performed by the same physician within the same day. However, they are billed on separate claims.
In contrast, modifier 59 reports a distinct or unrelated procedure performed within the same day as other services. These services are usually not reported together and require proper documentation.
Session / Patient Encounter
Modifier 51 applies to multiple procedures performed within the same session. On the other hand, modifier 59 indicates distinct services performed at a different patient encounter but within the same day as other services. These operations are completely unrelated and are performed at different anatomical areas.
Reimbursement Rates
With modifier 51, insurance companies only offer complete reimbursement for the first procedure. The additional surgeries are often reimbursed at a reduced rate because payers apply the multiple procedure payment reduction (MPPR) rules as per their policies.
Meanwhile, since modifier 59 points toward distinct operations, insurance companies reimburse them separately. Simply put, they offer complete payments for these unrelated services even when healthcare providers perform them on the same day.
Application Under NCCI Edits
This is another significant difference between modifiers 51 and 59. You can only apply modifier 51 to an additional procedure’s CPT code when there is no NCCI edit for a coding pair. Keep in mind that it is not suitable to append this modifier to add-on codes with a ZZZ global indicator.
In contrast, you can append modifier 51 when a PTP edit with a CCMI of 1 allows for unbundling with justified distinction.
Scenarios Where Modifiers 51 and 59 are Applicable
Consider the following scenarios if you are still confused between modifiers 51 and 59.
Scenarios Where Modifier 51 is Applicable
Always make sure to check NCCI’s rules before applying modifier 51 on any subsequent procedure.
Example #1: Removing Gallbladder & Appendix Together
A patient had problems with both their gallbladder and appendix at the same time. Therefore, a surgeon performed a laparoscopic cholecystectomy (CPT code 47562) and a laparoscopic appendectomy (CPT code 44970) together. In simple terms, he removed the patient’s gallbladder and appendix within the same session.
There is no NCCI restriction on this coding pair. And while the operations were different, they were performed in one operative session. Hence, the surgeon first billed CPT code 47562 as the primary procedure. He then appended modifier 51 to CPT code 44970 (44970-51), specifying it as an additional operation.
Example #2: Tracheostomy & Gastrostomy in a Single Session
A patient was on a ventilator after a serious injury. Therefore, a doctor performed percutaneous tracheostomy (CPT code 31600) and percutaneous endoscopic gastrostomy (CPT code 43246) within the same surgery.
These procedures helped the patient to breathe and eat on a ventilator. Since these procedures were performed within the same session, the surgeon filed CPT code 31600 as the primary operation and applied modifier 51 to CPT code 43246.
Scenarios Where Modifier 59 is Applicable
Example #1: Separate Chest & Abdominal CT Scans for Different Diagnoses
A patient with shortness of breath visits a radiologist for a chest CT scan. The radiologist performs the diagnostic procedure of the thorax (CPT code 71250). The patient later visited the same radiologist for an abdominal CT scan (CPT code 74150) due to a completely unrelated issue.
Both diagnostic tests were conducted by the same radiologist on the same day but in different sessions. Hence, the billing team applied modifier 59 to the second procedure (74150-59) to indicate that the tests were unrelated.
Example #2: Separate Eye and Ear Procedures on the Same Day
A patient with multiple ENT medical issues underwent two procedures on the same day. First, an otolaryngologist performed an evisceration (CPT code 65091) to remove the damaged inner content of the patient’s eye. Later that day, the same doctor removed a foreign object from the patient’s ear canal (CPT code 69200).
Since both services were distinct and unrelated, the otolaryngologist applied modifier 59 to the second procedure (69200-59) to request complete reimbursement.
Summary – Modifier 51 vs 59
Modifiers are an important part of medical coding. However, with so many restrictions and ever-changing requirements, it is quite challenging to use them correctly. Modifiers 51 and 59 are a perfect example of that. They may seem simple with their straightforward descriptions, but applying them correctly to different coding pairs can be a nightmare, especially with NCCI’s Procedure-to-Procedure edits.
The good news is that Medicare has simplified this process by removing the requirement for modifier 51. Hence, you no longer need to add this two-digit code to your subsequent procedures. Medicare’s processing system automatically appends it to the appropriate CPT codes.
