Physical therapy (PT) billing is rarely straightforward. Just when you think you have a handle on the Medicare 8-minute rule or Correct Coding Initiatives (CCI) edits, a new requirement is introduced to complicate your revenue cycle management. That’s what happened when the Centers for Medicare and Medicaid Services (CMS) created the CQ modifier.
The time-based calculation for this modifier is confusing and leads to many denials. Hence, to help you understand the accurate usage of modifier CQ in PT billing, we have written this detailed guide. So, let’s start.
CQ Modifier – Description
Modifier CQ is defined as:
“Outpatient physical therapy services furnished in whole or in part by a physical therapist assistant.”
To put it simply, the CQ modifier is a billing code that tells the payers (specifically Medicare) that a service was performed “in whole or in part” by a Physical Therapist Assistant (PTA). Before this modifier, payers didn’t have any way of differentiating between the services of a licensed Physical Therapist (PT) and a PTA.
This changed with the Bipartisan Budget Act of 2018 (Section 53107). Congress mandated that CMS establish a system to pay for assistant-provided services at a different rate than therapist-provided services. To make this operational, CMS created two new modifiers:
- CQ: For services furnished in whole or in part by a Physical Therapist Assistant (PTA).
- CO: For services furnished in whole or in part by an Occupational Therapy Assistant (OTA).
The definition seems simple enough. However, in reality, modifier CQ can be difficult to grasp. That’s usually because of the condition “in whole or in part”. Let’s break down what that actually means:
- In Whole: This is the easy part. If a PTA provides the entire service (100% of the minutes) without the PT’s direct involvement in that specific treatment code, you must apply the CQ modifier.
- In Part: This applies when a PTA provides a portion of the service. CMS uses a “de minimis” standard here. If the PTA renders more than 10% of the service independently, the CQ modifier applies.
Now, since we have mentioned the “de minimis” rule, let’s briefly discuss it here. This rule is deeply connected to Medicare’s 8-minute rule. Now, to determine if you need the modifier CQ based on this rule, you look at the total time for that code. If the PTA’s contribution exceeds 10% of the total time, the modifier is required.
For a standard 15-minute unit, 10% is 1.5 minutes. So, if a PTA performs 2 minutes or more of independent work on a unit, the CQ modifier must be used. However, an essential point to note here is that if the PT and PTA are treating the patient simultaneously, CQ should not be used.
Scenarios Where a CQ Modifier is Applicable
Theory is fine, but you need to know how it appears on a claim form. So, let’s look at a couple of real-world scenarios in which this code can be used:
Scenario 1: PTA Provides Entire Service Independently
For our first scenario, suppose that a PTA provides 30 minutes of Therapeutic Exercise (CPT 97110) to a patient. The supervising PT is in the clinic but does not participate in the exercise.
Billing: The exercises were performed for 30 minutes in total, which equals 2 units.
Since the PTA provided 100% of the service, the CQ modifier applies to both units.
Line Item: 97110 – GP – CQ (2 Units)
Scenario 2: PTA Provides More Than 10% of a Single Unit
Now, consider our second scenario in which the PT initiates a treatment and later delegates it to a PTA.
Suppose a physical therapist provides 5 minutes of therapeutic exercise. However, during the session, the PT has some urgent work to do. So, the assistant therapist takes over and provides 10 minutes of the same service. The total time is 15 minutes.
The Math:
- Total time: 15 minutes (1 unit).
- PTA time: 10 minutes.
- Calculation: 10 divided by 15 equals 66.67%.
Since 66.67% is greater than the 10% de minimis threshold, the CQ modifier applies.
Billing: 97110 – GP – CQ (1 unit)
CQ Modifier – Billing Guidelines
For proper reimbursement and to avoid claim denials, you must pay attention to the details and follow specific billing guidelines. The following are some essential points to keep in mind while using the CQ modifier:
Pairing Requirement
One of the most common reasons why billers face a denial for modifier CQ is a pairing issue. You must note that the CQ modifier cannot be applied standalone. It must be paired with the GP modifier, which indicates that the services were delivered under an outpatient physical therapy plan of care.
Also, the correct sequencing of these modifiers is essential. Always list the payment modifier (CQ) after the therapy plan of care modifier (GP). The accurate order on the claim form (Box 24D on the CMS-1500) is:
CPT Code – GP – CQ.
Not following this sequence will result in a denial.
Payment Reduction
Modifier CQ reduces the actual payment of the procedure by 15%. The 15% reduction is applied to the Medicare Physician Fee Schedule (MPFS) amount. Therefore, that particular code is reimbursed at 85% of the payment rate.
Documentation Requirements
Documentation is key if you want your claims to be reimbursed. As you have already seen, CQ modifier requirements and calculations can be complex, so Medicare requires detailed documentation to validate its use. Your notes should clearly indicate:
- Total treatment time.
- Specific interventions performed.
- Who performed what: If a PT and PTA split a service, the therapy notes must clearly delineate how many minutes the PTA provided versus the PT.
Summary
Finally, we have reached the end of this guide. We know that this is a lot of information to absorb, so let’s do a quick recap of the essential points:
- The CQ modifier is used to indicate the services of an assistant physical therapist.
- For proper usage and timing calculations, use the “de minimis” rule.
- Always use the code in the correct sequence with the GP modifier.
- Provide detailed documentation to back up your claims.
However, following the guidelines does not guarantee a 100% approval rate. Error-free billing requires experience and expertise in specialty-specific medical billing. If you are facing denials, you can rely on our medical billing services.
