Procedure Coding: When to Use the 59 Modifier

Many billers do not really understand modifiers or when they need to be used. Modifiers should be added to CPT codes when they are required to more accurately describe a procedure performed or service rendered.

A modifier should never be used just to get higher reimbursement or to get paid for a procedure that will otherwise be bundled with another code.

But modifiers can be tricky. Many times providers inappropriately use them, an abuse which inevitably leads to claim denials.  For our guide on the 3 most commonly misused modifiers, click here.

In this article, though, we’ll focus on the trickiest of them all, modifier 59.

The definition of the 59 modifier per the CPT manual is as follows:

Modifier 59: “Distinct Procedural Service” – Under certain circumstances, the physician may need to indicate that a procedure or service was distinct or independent from other services performed on the same day. Modifier 59 is used to identify procedures/services that are not normally reported together, but are appropriate under the circumstances. This may represent a different session or patient encounter, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same physician. However, when another already established modifier is appropriate, it should be used rather than modifier 59. Only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used.

When to Use the 59 Modifier
The 59 modifier is one of the most misused modifiers. The most common reason it should be used is to indicate that two or more procedures were performed at the same visit but to different sites on the body.

Unfortunately, many times it is used to prevent a service from being bundled or added in with another service on the same claim. It should never be used strictly to prevent a service from being bundled or to bypass the insurance carrier’s edit system.

59 should also only be used if there is no other, more appropriate modifier to describe the relationship between two procedure codes. If there is another modifier that more accurately describes the services being billed, it should be used instead of the 59 modifier.

When using the 59 modifier to indicate a distinct and separate service, documentation should be in the patient’s medical file that substantiates that the services were performed separately. The insurance carrier may request to review the record to deem if the 59 modifier is being appropriately used before reimbursing the full amount for the modified CPT code.

It’s important to note that use of the 59 modifier does not require that there be a different or separate diagnosis code for each of the services billed. As such, simply using different diagnosis codes for each of the services performed does not support the use of the 59 modifier.

59 Modifier Examples
An example of appropriate use of the 59 modifier might be if a physical therapist performed both 97140 (manual therapy) and 97530 (therapeutic activity) in the same visit. Normally these procedures are considered inclusive.

If the 59 modifier is appended to either code, they will both be allowed on the claim separately. However, the 59 modifier should only be added if the two procedures are performed in distinctly separate 15 minute intervals. If the therapist performs the procedures simultaneously, then the 59 modifier should not be used.

Another example would be if the patient were having a nerve conduction study with CPT codes 95900 and 95903 being billed. If the two procedures are done on separate nerves, then the 59 modifier should be used to indicate that. If the codes were performed on the same nerve, then the 59 modifier should not be used.

The biller should never be the one to add the 59 modifier to a claim, even if she knows that billing the services without the modifier will result in bundling or a denial. The 59 modifier should only be added by the provider or by a coder who has access to the patient’s chart.

If you are the biller and you believe that the 59 modifier would be appropriate but was not indicated, you should go back to the provider to see if it was omitted by mistake. Don’t just add the modifier to the claim without substantial evidence that it is needed.

Misusing 59, or any other modifier, can cause a payer to deny your claim altogether. Avoid claim issues by making sure to always use it properly.

Have you ever experienced a denial due to misuse of modifier 59? How was it resolved?

Alice Scott and Michele Redmond are medical billing experts, co-owners of Solutions Medical Billing Inc in Rome, N Y., and coauthors of 15 books on medical billing and medical credentialing. Their newest title is Advanced Medical Billing Marketing for the New Economy.

This mother-and-daughter team maintains two medical billing websites, a free newsletter and an active forum. Alice and Michele are on the editorial staff of BC Advantage and are regular contributors to the magazine. Their books are available at