Summary & Overview

HCPCS G8649: Knee Functional Status Survey Not Completed

HCPCS Level II code G8649 documents a risk-adjusted residual score for knee functional status when the patient did not complete the required functional status survey near discharge or was deemed not appropriate for survey completion. This code matters nationally because functional status measurement is integral to quality reporting and outcome comparisons across post-acute and inpatient settings; G8649 provides a standardized way to indicate an expected knee functional status score is unavailable due to patient factors rather than missing documentation.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find context on the clinical and administrative purpose of the code, typical sites of service where it is used, and the implications for outcome measurement and claims processing when knee functional status cannot be obtained. The summary also highlights how G8649 fits into functional status reporting workflows and where to expect its use in quality reporting and claims submissions.

The publication provides benchmarks and policy-relevant context for payers and providers, clarifies the clinical scenario that triggers use of the code, and outlines where additional coding or documentation typically resides. Data not available in the input will be identified as such rather than assumed.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareG8649HCPCS Level IIfunctional statusknee impairmentpost-acute carequality measurementdischarge assessmentoutcome reportingrisk adjustment

Billing Code Overview

HCPCS Level II code G8649 represents a risk-adjusted functional status change residual score for the knee impairment when the functional status (fs) survey was not completed near discharge because the patient did not complete the survey or the patient was not appropriate for the survey. The service type is a functional status outcome measurement assessment recorded when a knee-specific functional status score cannot be obtained at or near discharge.

Typical site of service: inpatient rehabilitation units, acute care hospitals, and post-acute care settings where functional status is routinely assessed at discharge but the survey was not completed or the patient was deemed not appropriate for survey completion.

Data not available in the input.

Clinical & Coding Specifications

Clinical Context

A typical patient is a 68-year-old individual admitted to an inpatient rehabilitation facility following total knee arthroplasty for advanced osteoarthritis. During the course of rehabilitation, physical therapy staff perform standardized functional status (FS) assessments at admission and near discharge to measure improvement in knee-related function. For this episode, the patient did not complete the near-discharge FS status survey because they were discharged early to home with home health services and declined the survey due to acute postoperative pain and fatigue. The care team documents that the patient was not appropriate for the near-discharge FS assessment due to clinical instability and incomplete participation. The billing action is to report the HCPCS Level II code G8649 to indicate a risk-adjusted functional status change residual score for the knee impairment was not measured because the patient did not complete the FS status survey near discharge and was not appropriate for assessment.

Coding Specifications

Modifier	Description	When to Use
`24`	Unrelated evaluation and management service by the same physician during a postoperative period	Use when an unrelated E/M is provided during the global period; rarely applied to functional status reporting but included for clinical documentation clarity.
`25`	Significant, separately identifiable E/M service on the same day as a procedure	Use if a documented, separate E/M visit occurred the same day as functional status documentation activities.
`59`	Distinct procedural service	Use to indicate distinct services when procedural codes might overlap with functional assessment visits.
`76`	Repeat procedure or service by same provider	Use if the FS assessment was attempted previously and repeated documentation is required.
`77`	Repeat procedure or service by another provider	Use when another clinician repeats an assessment attempt.
`78`	Unplanned return to the operating room by the same physician following initial procedure	Use only if postoperative complications altered assessment timing and appropriateness.
`GG`	Reporting of functional limitation reporting (CMS modifier for some quality measures)	Use in contexts where facility or payer requires functional reporting; supports documentation that the FS score was not obtained.
`Q6`	Service furnished under a program of all-inclusive care for the elderly (PACE)	Use if the patient is enrolled in PACE and billing requires this designation.
`XE`	Separate encounter, a service distinct because it occurred during a separate encounter	Use when the noncompletion occurred during a distinct encounter unrelated to other billed services.
`XP`	Separate practitioner, a service distinct because it was performed by a different practitioner	Use when a different clinician attempted the FS survey and could not obtain it.

Taxonomy Code	Specialty	Notes
`173100000X`	Physical Therapist	Physical therapists commonly administer FS status surveys and document functional change for knee impairments.
`2086S0200X`	Physical Therapist Assistant	Assistants often conduct or assist with survey administration under PT supervision.
`207L00000X`	Sports Medicine Physician	Physicians in orthopedic/sports medicine oversee knee recovery and functional outcome measurement.
`207K00000X`	Orthopedic Surgeon	Orthopedic surgeons manage surgical patients and review functional outcome documentation for knee procedures.
`261QM0800X`	Rehabilitation Physician (PM&R)	Physiatrists coordinate multidisciplinary inpatient rehab programs and functional status reporting.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`M17.11`	Unilateral primary osteoarthritis, right knee	Common diagnosis for patients undergoing knee rehabilitation and FS status measurement.
`M17.12`	Unilateral primary osteoarthritis, left knee	As above, for the contralateral knee when presenting for rehabilitation.
`M17.0`	Bilateral primary osteoarthritis of the knee	Bilateral disease often requires comprehensive functional assessment to document change.
`M17.9`	Osteoarthritis of knee, unspecified	General knee osteoarthritis diagnosis associated with functional assessments.
`M17.5`	Other secondary osteoarthritis of knee	Secondary causes of knee OA influence functional progress and appropriateness of FS surveys.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`97110`	Therapeutic exercises to develop strength and endurance, range of motion and flexibility (per 15 minutes)	Commonly performed by physical therapy to improve knee function; supports admission/discharge FS assessments.
`97112`	Neuromuscular reeducation of movement, balance, coordination, kinesthetic sense, posture, and proprioception (per 15 minutes)	Performed during rehabilitation for knee impairment; contributes to functional status change measurements.
`97530`	Therapeutic activities, direct (one-on-one) patient contact (per 15 minutes)	Functional task-oriented therapy used to address ADL and mobility limitations related to knee impairment.
`92610`	Swallowing function (not directly related)	Data not available in the input.
`G0151`	Services performed by a qualified physical therapist in the home health or hospice setting, each 15 minutes	Relevant when the patient transitions to home health and FS assessment cannot be completed at discharge.