What Is the CQ Modifier for Physical Therapy Services?

Medical modifiers are short codes added to procedure codes, such as CPT or HCPCS codes, to provide additional information about a service or procedure. These modifiers clarify specific circumstances that affect payment, indicating details that may not be apparent from the primary code alone. Modifier CQ is one such specific modifier used in healthcare billing. Its primary purpose relates to outpatient physical therapy services provided by a physical therapist assistant, signifying their involvement in the delivery of care.

Understanding Modifier CQ

Modifier CQ stands for “Outpatient physical therapy services furnished in whole or in part by a physical therapist assistant (PTA)”. This modifier is specifically designed to indicate when a physical therapist assistant has provided physical therapy services. The term “in whole” means the PTA furnished the entire service or procedure, accounting for 100% of the total treatment time. “In part” refers to situations where the PTA’s contribution exceeds a de minimis portion of the therapy service, typically more than 10% of the total service time.

This modifier was established by the Centers for Medicare & Medicaid Services (CMS) to distinguish services provided by a PTA from those delivered solely by a licensed physical therapist. Its existence helps ensure accurate billing and allows for appropriate payment adjustments based on the level of provider involvement.

When Modifier CQ is Applied

Modifier CQ is applied to claims for outpatient physical therapy services when a physical therapist assistant furnishes services either entirely or partially. This requirement became effective for claims with dates of service on and after January 1, 2020. Providers such as outpatient hospitals, rehabilitation agencies, skilled nursing facilities, home health agencies, and comprehensive outpatient rehabilitation facilities typically use this modifier.

When applying the modifier, it must be reported on the claim line alongside the GP therapy modifier, which identifies services furnished under a physical therapy plan of care. Services subject to this modifier are paid at a reduced rate, specifically 85% of the otherwise applicable Medicare Part B payment for the service, effective January 1, 2022.

Documentation Supporting Modifier CQ Use

Proper documentation is necessary for justifying the use of Modifier CQ on a claim. While CMS did not establish new documentation requirements specifically for this modifier, existing therapy documentation rules apply. Medical records must clearly indicate the date of treatment and identify each specific intervention provided and billed. This detail allows for verification of correct coding when compared with the claim submission.

Documentation should also support the medical necessity for the services rendered and clearly show the portion of the service provided by the physical therapist assistant. For timed services, records must detail the minutes provided by the PTA, especially if it meets or exceeds the de minimis standard (more than 10% of the service time). Comprehensive records ensure that the billed services align with the actual care delivered and meet payer requirements.

Claim Submission with Modifier CQ

Submitting a claim with Modifier CQ involves appending it to the appropriate HCPCS or CPT code for the physical therapy service. On a paper claim form, such as the CMS-1500, Modifier CQ is typically placed in Box 24D, in the modifier field, next to the CPT/HCPCS code. For electronic claims submitted via an 837P transaction, the modifier is entered in the appropriate electronic equivalent field, often within the 2400 loop, SV1 segment.

The CQ modifier must be paired with the GP therapy modifier on the same claim line. Claims submitted without this pairing may be rejected or returned as unprocessable.