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5 Things Physical Therapists Need to Know About Modifier 59

Wondering about how to bill for separate and distinct services provided at the same time? Wonder no more, as we lay out what you need to know about modifier 59.

Charlotte Bohnett
5 min read
April 3, 2024
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One of the primary reasons medical providers depend on certified coders is that coders know how to maximize practice revenues. That’s because certified coders understand how and when to use modifiers—and there are a lot—to indicate anything from laterality (e.g., right [RT] and left [LT]), to separate and distinct procedures. With the latter, I’m of course referring to the very real questions regarding modifier 59. A physical therapist isn’t a certified coder, and yet, when it comes to questions about the 59 modifier definition or use, they essentially need to be. That’s because few modifiers cause as much confusion for PTs or wreak as much havoc on their payments as this mysterious modifier. In this post, I’ll demystify modifier 59 by detailing how and when physical therapists should use it. Here’s what PTs need to know about the proper use of modifier 59.

1. Most of the guidelines on Modifier 59 are predominantly intended for surgical procedures.

The Current Procedural Terminology (CPT) Manual defines modifier 59 as the following: “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 [and/or] 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."

If you think that definition is not only dense but also ill-fitting for rehab therapy providers, then you’re correct on both counts. In short, Modifier 59 is meant for a distinct procedural service not normally performed at the same time as another — but if a more descriptive modifier is available, you should use that one. Modifier 59 is intended mainly for surgical procedures, and that’s reflected in the CPT Manual’s definition. Don’t let that mislead you on the importance of modifier 59 for rehab therapists, though; you may encounter the 59 modifier in physical therapy billing.

2. Modifier 59 is used in conjunction with edit pairs.

So, how does modifier 59 come into play in the therapy setting? If you’re providing two wholly separate and distinct services during the same treatment period, it might be modifier 59 time! The National Correct Coding Initiative (NCCI) has identified procedures that therapists commonly perform together and labeled these “edit pairs.” Thus, if you bill a CPT code that is linked to one of these pairs, you’ll receive payment for only one of the codes. It’s your responsibility as the therapist to determine whether you’re providing linked services or wholly separate services. This, in turn, will determine whether modifier 59 is appropriate. As Brooke Andrus explains in this blog post, “When you append modifier 59 to one of the CPT codes in an edit pair, it signals to the payer that each service performed in the pair was done separately and independently of one another—meaning that you also should receive separate payment for each procedure.”

3. In 2021, CMS agreed to reimburse several former NCCI edit pairs without modifier 59.

At the behest of the APTA, the Center for Medicare and Medicaid Services (CMS) has agreed to pay providers for the following commonly paired services without the application of modifier 59. According to the APTA, this change is, “expected to reduce the use of code modifiers that were creating confusion and sparking claim denials,” which is a big win for everyone involved. Thus, providers can perform the following services—and receive reimbursement—without affixing a modifier:

  • 97110 with 97164
  • 97112 with 97164
  • 97113 with 97164
  • 97116 with 97164
  • 97140 with 97164
  • 97150 with 97164
  • 97530 with 97116
  • 97530 with 97164
  • 99281-99285 with 97161-97168
  • 97161-97163 with 97140
  • 97127 with 97164
  • 97140 with 97530
  • 97530 with 97113

Of course, even if you’re careful about coding with modifier 59, you could still find yourself in a situation where your claim is denied. As WebPT billing expert John Wallace laid out in How to Handle Modifier 59 Denials for 97530 and 97140, CMS is looking for appropriate documentation to reflect the use of these modifiers.   

4. WebPT can tell you when to add modifier 59.

Too often, PTs receive denied claims or insufficient payments because of improper modifier 59 use. That’s why we developed a feature (aptly named Built-In NCCI Edits) that will check your codes against the Medicare NCCI rules as you add services to be billed for each visit. Once you’ve turned on this feature, it will notify you of any NCCI edit pairs entered for the same date of service. If your documentation justifies billing both codes, you can acknowledge this, and WebPT immediately adds modifier 59 to the appropriate code. Pretty nifty, right?

Activating Built-In NCCI Edits within WebPT

To activate this feature, please follow the steps below. Note that you’ll need to complete these steps for each insurance plan. We recommend applying this to commercial and government plans only (i.e. no workman’s compensation, legal/lien, and auto liability policies).

  1. Select “Display Insurance,” located on the left side of the WebPT Dashboard.
  2. Click “Edit” on the individual insurance for which you want to activate the feature.
  3. Once the insurance editing screen opens, check “Apply CCI edits”; then, select “Save.”

If you’re not yet a WebPT Member, you can see this functionality and an array of other awesome features in our free, live online demonstration

5. Modifier 59 isn’t your billing-free card.

You should apply modifier 59 to denote when you have provided a typically bundled service wholly separate from its counterpart. That’s it. You shouldn’t use modifier 59 to guarantee higher reimbursement, nor should you purposefully skimp on your documentation or intentionally document vaguely or misleadingly. Additionally, do not routinely use modifier 59 in conjunction with re-evaluation codes because doing so could raise a red flag to your payers.

As WebPT billing expert John Wallace laid out in How to Handle Modifier 59 Denials for 97530 and 97140, overuse of modifiers 59 and 25 led private payers like Anthem, Aetna, and Humana to adopt front-end claim edit policies for any claims with those modifiers. While the policies have been updated, the change caused several denials for providers using those claims—even in cases where the modifiers were correctly affixed. 

As Wallace notes, if you’ve used modifier 59 appropriately and had your claim denied, you should appeal the decision—assuming your documentation demonstrates proper use. Ideally, your documentation should include:

  • Interventions that apply to each CPT code and are grouped appropriately; 
  • One-on-one and total treatment time in minutes for therapy and therapeutic activities;
  • The body part involved in an intervention; and
  • A version of the statement “The manual therapy interventions were performed at a separate and distinct time from the therapeutic activities interventions.” 

There you have it: the five things you, as a PT, need to know on modifier 59. Of course, rules are always changing—so check back here in the future for updates!

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