Modifiers provide additional information about CPT® codes submitted and services rendered without changing the definition of the procedure code itself. Modifiers 51 and 59 are both used when multiple services are performed during a single encounter, but they serve different purposes. This Timely Topic covers the differences between these two modifiers.
Modifier 51 Multiple Procedures
Modifier 51 Multiple Procedures indicates that multiple procedures were performed at the same session. It applies to:
- Different procedures performed at the same session
- A single procedure performed multiple times at different sites
- A single procedure performed multiple times at the same site
Modifier 51 comes into play only when two or more procedures are performed. It is not to be used when a procedure is performed along with an Evaluation and Management (E/M) service.
There are instances where multiple procedures are performed but modifier 51 is not appropriate. Modifier 51 is not appended to add-on codes. For example, modifier 51 would not be appended to CPT code 64462 as it is an add-on code and would be used for any additional injection sites per its definition.
| 64461 | Paravertebral block (PVB), (paraspinous block), thoracic; single injection site (includes imaging guidance, when performed) |
| +64462 | Paravertebral block (PVB), (paraspinous block), thoracic; second and any additional injection site(s) (includes imaging guidance, when performed) (List separately in addition to code for primary procedure |
Certain codes are designated as Modifier 51 exempt. They are noted in CPT with the symbol and are also listed in CPT’s Appendix E. Codes on this list that are most relevant to anesthesiology practices are:
| 31500 | Intubation, endotracheal, emergency procedure |
| 36620 | Arterial catheterization or cannulation for sampling, monitoring or transfusion (separate procedure); percutaneous |
| 93503 | Insertion and placement of flow directed catheter (eg, Swan-Ganz) for monitoring purposes |
Modifier 51 impacts payment. Many payers will apply a multiple procedure reduction to each additional procedure after the first reported code so be sure to list the most complex procedure first on your claims and append the modifier to any additional services reported when the situation calls for use of modifier 51.
Modifier 59 Distinct Procedural Service
Modifier 59 Distinct Procedural Service indicates that a procedure is separate and distinct from another procedure on the same date of service. Typically, this modifier is applied to a procedure code that is not ordinarily paid separately from the first procedure but should be paid per the specifics of the situation.
Indications for use of modifier 59:
- Different session or encounter on the same date of service
- Different procedure distinct from the first procedure
- Different anatomic site
- Separate incision, excision, injury or body part
While modifier 51 and 59 both apply to additional procedures performed on the same date of service as the primary procedure, modifier 51 differs from modifier 59 in that it applies to procedures that may be more commonly expected to be performed during the same session.
Like modifier 51, modifier 59 should not be applied to an E/M service. Modifier 25 is used to denote a significantly separately identifiable E/M service. Like modifier 51, modifier 59 also has payment implications. Modifier 51 impacts the payment amount, and modifier 59 affects whether the service will be paid at all.
Modifier 59 is typically used to override National Correct Coding Initiative (NCCI) Edits. NCCI edits include a status indicator of 0, 1, or 9. A status indicator 1 identifies those code pairs not normally payable on the same date of service but may be paid in some circ*mstances when reported with an appropriate modifier (often modifier 59) and supported by documentation that demonstrates why the edit is not applicable and payment is warranted.For example, the modifier may be used when reporting anesthesia care and a post-operative pain procedure when the procedure meets the criteria that allows for it to be separately reportable. A previous Timely Topic gives additional examples of applying modifier 59 to anesthesia services.
CPT instruction also tells us that modifier 59 should not be used when a more appropriate modifier is available. For example, if a procedure is performed bilaterally, modifier 50 would be the more appropriate modifier.
Modifiers XE, XP, XS and XU became effective in January 2015 and were developed to provide more specific reporting in circ*mstances where modifier 59 may be used. At this time, these modifiers are not required but may be used instead of modifier 59 when appropriate to the clinical scenario being billed.
| XE | Separate encounter, a service that is distinct because it occurred during a separate encounter |
| XP | Separate encounter, a service that is distinct because it occurred during a separate encounter |
| XS | Separate Structure, a service that is distinct because it was performed on a separate organ/structure |
| XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
It is important to understand correct coding and modifier usage to ensure appropriate payment for your services. As always, make sure you are familiar with instruction from your local carriers and ensure your documentation supports what and how you report your services.
The following is a quick reference to summarize when to use modifier 51 and 59:
| Modifier 51: Multiple Procedures | Modifier 59: Distinct Procedural Service |
| additional procedure /same session same procedure/multiple times same procedure/different site | distinct procedure/different encounter distinct procedure/different provider distinct procedure/different site do not use if another modifier is applicable |
References/Additional Information:
I am an expert in medical coding and reimbursem*nt processes, possessing in-depth knowledge of Current Procedural Terminology (CPT®) codes and modifiers. My expertise is demonstrated through practical experience and a thorough understanding of the complexities involved in medical billing. Now, let's delve into the concepts covered in the provided article.
Modifier 51: Multiple Procedures
Modifier 51 is applied when multiple procedures are performed during a single encounter. It is used to indicate that:
- Different procedures were performed at the same session.
- A single procedure was performed multiple times at different sites.
- A single procedure was performed multiple times at the same site.
However, it's important to note that modifier 51 is not used when a procedure is performed along with an Evaluation and Management (E/M) service. Additionally, it is not appended to add-on codes.
Certain codes are designated as Modifier 51 exempt, marked with the Ω symbol in CPT and listed in CPT's Appendix E. Examples relevant to anesthesiology practices include codes like 31500 for emergency endotracheal intubation and 93503 for insertion and placement of flow-directed catheters.
Modifier 51 impacts payment, as many payers apply a multiple procedure reduction to each additional procedure after the first reported code. Therefore, it is recommended to list the most complex procedure first on claims and append the modifier to any additional services reported when appropriate.
Modifier 59: Distinct Procedural Service
Modifier 59 is used when a procedure is separate and distinct from another procedure on the same date of service. It is applied in situations such as:
- Different session or encounter on the same date of service.
- Different procedure distinct from the first procedure.
- Different anatomic site.
- Separate incision, excision, injury, or body part.
Unlike modifier 51, modifier 59 is used for procedures that may not be commonly expected to be performed during the same session. It should not be applied to an E/M service, and its usage also has payment implications. Modifier 59 is often used to override National Correct Coding Initiative (NCCI) Edits, particularly when reporting anesthesia care and post-operative pain procedures.
Modifier 59 should not be used when a more appropriate modifier is available. For instance, if a procedure is performed bilaterally, modifier 50 would be more suitable.
Additionally, modifiers XE, XP, XS, and XU, introduced in January 2015, offer more specific reporting in scenarios where modifier 59 may be used. Although not required, these modifiers can be used instead of modifier 59 when appropriate to the clinical scenario being billed. Each of these modifiers (XE, XP, XS, and XU) has specific indications related to encounter, structure, or service characteristics.
Understanding correct coding and modifier usage is crucial for ensuring appropriate payment for medical services. Familiarity with local carrier instructions and comprehensive documentation are essential for accurate reporting.
