RTM Billing Modifiers Explained — KX, CQ and Place of Service 11
When billing for Remote Therapeutic Monitoring (RTM) services, correct modifier use is just as important as selecting the right Current Procedural Terminology (CPT) code. Applying the wrong modifier — or forgetting one entirely — can result in claim denials, payment delays, or compliance risks.
In this guide, we break down the three most common modifiers and location codes used for RTM billing: KX, CQ, and place of service (POS) 11. You’ll learn what each means, when to apply it, and common mistakes to avoid.
Why Modifiers Matter in RTM Billing
Modifiers provide additional context to payers about how and where a service was delivered. In RTM, they often indicate:
Whether a therapy cap has been met (KX)
The involvement of a physical therapist assistant (CQ)
The physical location where the service was furnished (place of service 11)
Without the correct modifiers, even a properly documented RTM service can be rejected.
KX Modifier — Therapy Cap Exception
The KX modifier is used to signal that services are medically necessary even though the patient has reached or is approaching the therapy cap.
When to use it for RTM:
The patient is at or near the therapy cap
The provider has documentation supporting medical necessity for continued services
The service being billed is covered under therapy services, including RTM CPT codes like 98975, 98977, 98980, and 98981
Example: A patient recovering from a total knee arthroplasty has reached the therapy cap but still requires RTM monitoring for post-op rehabilitation. The KX modifier ensures payment if documentation supports the medical need.
CQ Modifier — Services Furnished by a PTA
The CQ modifier indicates that more than 10% of a service was furnished by a physical therapist assistant (PTA) under the supervision of a physical therapist (PT).
When to use it for RTM:
Required for CPT 98975 if a PTA provides >10% of the initial setup and education
Required for CPT 98980 or 98981 if a PTA contributes >10% of the treatment management time
Not required for CPT 98977, regardless of who monitors the device
Example: If a PTA conducts most of the RTM patient onboarding session, CPT 98975 would need the CQ modifier to comply with CMS rules.
Place of Service 11 — Office
The place of service (POS) 11 code identifies where the service was provided. For RTM, POS 11 is used when the billing provider’s office is the designated service location.
When to use it for RTM:
The provider’s office is the main point of service for the RTM program
The device was issued and/or patient education occurred in the office setting
The payer requires a POS code for claim processing
Common Modifier Mistakes in RTM
Forgetting to add the KX modifier when the patient is at the therapy cap
Applying the CQ modifier to CPT 98977 when it is not required
Using the wrong place of service code, especially for hybrid or telehealth RTM programs
Not including documentation that supports why the modifier was used
How Orva Helps Prevent Modifier Errors
Orva’s RTM platform integrates modifier logic into its billing reports. The system flags when KX or CQ should be applied and automatically assigns the correct POS code, reducing the chance of human error and denied claims.
Key Takeaway
Correct use of the KX, CQ, and POS 11 codes ensures your RTM claims are processed smoothly and paid promptly. Combining proper documentation with the right technology can significantly reduce billing headaches.
Are you ready to move from learning about RTM to implementing a successful RTM program? Schedule a demo today to see how Orva is the perfect partner for serious practices.