New PTA and OTA Modifiers Effective January 1, 2020

Author: Paul Singh

Now that 2020 is here, there is a new CMS rule that will affect your physical therapy practice, and it includes PTA and OTA modifiers.  These modifiers went into place on January 1st, 2020.


To say that there are concerns about the new ruling with the American Physical Therapy Association (APTA) and the American Occupational Therapy Association (AOTA) is an understatement, and there are some questions that will still need to be ironed out.  Nevertheless, the rule is upon us.  This involves when a therapy assistant provides a service that is “in whole or in part”.  The service line on the Medicare Part B claim must include one of the following two payment modifiers:

  1. CQ (for PTAs)
  2. CO (for OTAs and COTAs)

Looking ahead, if the rule stands, once we reach the year 2022, CMS will start reducing reimbursements for services that have an assistant modifier by 15%.

These modifiers will apply to all outpatient services that are paid under the Medicare Physician Fee Schedule, including those provided inpatient facilities, such as CORFs, SNFs and HHAs.  The modifiers will also apply to those who provide outpatient services in rural and underserved areas, but won’t apply to services furnished in critical access hospitals or billed incident-to a physician or NPP.


Determining when an assistant provided a “whole” service is fairly easy to figure out.  What becomes more difficult is determining if an assistant provided a service “in part”, per CMS specifications.

Keep the following in mind – if an assistant provides more than 10% of a service, CMS deems it “in part” by the assistant.  Therefore, the associated claim line should contain an assistant payment modifier. However, this is where it gets a little trickier.  The 2020 final rule spells out that only the minutes that a PTA or OTA treats independently from the therapist counts toward the 10%.  That means that the assistant modifiers would not apply when the therapist and assistant provide treatment at the same time.


Always trying to be helpful, CMS offered two formulas that providers can use to determine if they need to apply an assistant modifier or not.  Here are the two formulas:

Formula A:

  1. Divide the number of minutes that a PTA or OTA independently furnished a service by the total number of minutes the service was furnished as a whole.
  2. Multiply that number by 100.
  3.  Round to the nearest whole number.
  4. If the final total is 11% or greater, apply the CQ or CO modifier.

Formula B:

  1. Divide the total number of minutes that the service was furnished by ten.
  2. Round to the nearest whole number.
  3. Add one minute to the total.
  4. If the PTA or OTA furnished care independently of a therapist for longer than the final total, apply the CQ or CO modifier.


Sorting out the new modifiers and the mathematical formulas can be confusing.  After all, the provision of therapy services isn’t always black and white, there are gray areas to contend with.  StrataPT is here to help.  We can answer your tough questions and provide solutions that are perfect for your business model.  We offer revenue cycle management for physical therapy practices.  Whether you are just starting out or are well established, StrataPT offers outpatient physical and occupational therapy practices with the true all-in-one solution.

Contact us today and request a demo.  You will see why our services include a unique blend of user-friendly scheduling, documentation and practice management software that is seamlessly integrated with our industry-leading billing, insurance credentialing and benefit verification services.  Our friendly team members look forward to learning more about you and your practice!

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