Functional Data Collection Requirements for Outpatient Therapy


Jennifer Hitchon, Counsel & Director of Regulatory Affairs for AOTA, discusses these Medicare reporting requirements in a podcast (recorded June 14, 2013) with accompanying slides available here.

As of July 1, 2013, occupational therapists billing for outpatient therapy services under Medicare Part B must report functional data on their claims in order to be reimbursed. Functional data reporting takes the form of new G-codes, which identify the primary issue being addressed by therapy, and modifiers that reflect the patient’s impairment/limitation/restriction. The data will be used to track functional change over time.

Voluntary reporting began on January 1 with a six-month testing period. On July 1, reporting became mandatory and Centers for Medicare & Medicaid Services (CMS) contractors stopped accepting claims without the required functional data and began returning them for re-submission with the required codes. 

This functional data reporting requirement was mandated by statute and implemented via regulation. CMS first proposed this requirement in July 2012 (AOTA published an Analysis of the Proposed Rule at the time, and submitted a Comment Letter to CMS) and finalized it in the November 2012 Physician Fee Schedule Final Rule for CY 2013, which creates and amends regulations governing payment practices for Medicare Part B outpatient therapy services in CY 2013. 

G-Code Categories

Below are the G-code categories that therapists may use. (For the full list of 42 G-codes, see here (final rule) or here (1-page CMS Fact Sheet). Occupational therapists can use any and all of these 42 codes, and should select the G-code set for the functional limitation that most closely relates to the primary functional limitation being treated or the one that is the primary reason for treatment. If your facility is instructing you otherwise - or you have questions about occupational therapy’s right to report G-codes for swallowing, attention, memory, etc. - please contact AOTA at There is no restriction by discipline.

Mobility: Walking & Moving Around
Changing & Maintaining Body Position
Carrying, Moving & Handling Objects
Self Care
Other PT/OT Functional Limitation
Other SLP Functional Limitation
Motor Speech
Spoken Language Comprehension
Spoken Language Expression

Severity/Complexity Modifiers


Impairment/ Limitation/ Restriction















This scale of 7 modifiers is intended to denote the patient's degree of impairment/limitation/restriction. This final scale has been reduced and simplified by CMS, as per AOTA request, from the original 12 proposed modifiers.

Frequently Asked Questions (FAQs)

Q: Who must report?

A: The professionals required to report G-codes and modifiers on the claim form include occupational therapists; physical therapists; speech-language pathologists; physicians; and certain nonphysician professionals, such as physician assistants, nurse practitioners, and clinical nurse specialists. 

Q: How do I select the appropriate G-code?

A: When a beneficiary has more than one functional limitation, as is often the case, the therapist may need to make a determination as to which functional limitation is primary. In these cases, the therapist may choose the functional limitation that is:  

  • Most clinically relevant to a successful outcome for the beneficiary; 
  • The one that would yield the quickest and/or greatest functional progress (e.g., select “mobility” over “self-care” even though both are addressed simultaneously if the therapist expects the patient to attain their mobility goals before their self-care goals); or
  • The one that is the greatest priority for the beneficiary.  

Occupational therapists can select a code from any of the G-code functional categories (mobility, changing & maintaining body position, self-care, attention, memory, carrying/moving/handling objects, etc.). The categories are not discipline-specific.

Q: How many G-codes do I use?

A: Typically you will report only one primary functional limitation at a time, using one G-code at a time. A second functional limitation will be reported for patients who have reached his or her goal, or progress has been maximized on the initially reported functional limitation, but the need for treatment continues. So while reporting on more than one functional limitation may be required for some patients, it will only overlap and not be done simultaneously in full.

Q: How do I select the appropriate modifier?

 You should always use your clinical judgment in the assignment of the appropriate modifier. Therapists should document in the medical record how they made the modifier selection so that the same process can be followed at succeeding assessment intervals. A therapist may use a modifier that reflects the patient’s score on the functional assessment tool or other performance measurement instrument used. MediServe has made available a free functional modifier mapping tool and conversion calculator to help providers with the modifier selection process. The tool is provided as a resource to you and is available here.

Q: How do I report patients whose functional status will not change, or will change very little?

 In some cases for beneficiaries where improvement is expected to be limited, the same severity modifier may be used in reporting the current and goal status. In cases where the occupational therapist does not expect improvement, such as for those individuals receiving skilled maintenance therapy, the modifier used for projected goal status will be the same as the one for current status.

Q: How often do I report G-codes and modifiers?

A: The functional reporting period matches the progress reporting period. CMS has made changes to the progress reporting period, effective January 1, 2013. Currently, the rule is that therapists report once every 10th treatment day or every 30 calendar days, whichever is less. Under new rules beginning in 2013, therapists must report once on or before the 10th treatment day. Functional reporting must thus occur at the following times:

  • At the outset of a therapy episode of care (i.e., on the claim for the date of service (DOS) of the initial therapy service)
  • At least once every 10 treatment days 
  • When an evaluative procedure is furnished and billed (CPT codes 97003 & 97004)   
  • At the time of discharge from the therapy episode of care
  • At the time reporting of a particular functional limitation is ended (and further therapy is necessary) 
  • At the time reporting is begun on a different (second, third, etc.) functional limitation 

Q: When do I have to start reporting? Will my claims be denied if I fail to affix a code and modifier to my claim?

 While reporting began on January 1, 2013, in accordance with the authorizing statute, the first 6 months of the year served only as a testing period during which providers could acclimate to the change. As of July 1, 2013, CMS will reject claims that do not include the required G-codes and modifiers. 

Q: What are the documentation requirements?

CMS is requiring that documentation of the G-codes and severity modifiers used in complying with the Functional Reporting requirements must be included in the beneficiary's medical record of therapy services for each required reporting. 

Q: Who can document?

A: Required documentation must be completed by:  

  • The qualified occupational therapist furnishing the therapy services
  • The qualified occupational therapist furnishing services incident to the physician/NPP
  • The physician/NPP personally furnishing the therapy services


If you have additional questions, please email AOTA's Regulatory Affairs Department at or email CMS directly at

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