Summary & Overview
HCPCS M1338: Follow-up Functional Assessment, No Improvement (30–180 days)
HCPCS Level II code M1338 denotes a follow-up functional assessment conducted 30 to 180 days after an initial (index) assessment for patients who did not show improvement or maintenance of functioning scores during the performance period. The code is used to document outcome-focused reassessment when expected functional gains are not achieved, supporting clinical tracking and payer review of continued need for services. Nationally, such outcome-assessment codes matter for care management, utilization review, and quality measurement tied to functional recovery pathways.
Key payers examined include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the code’s clinical intent, typical service settings, and the payers commonly involved in coverage decisions. The publication outlines where M1338 fits in clinical workflows, typical billing contexts, and the types of reporting or audit focus that can accompany follow-up outcome assessments.
This analysis provides benchmarks and policy context relevant to claims processing and quality measurement, summarizes common modifiers and billing considerations supplied in the input, and highlights gaps in publicly provided taxonomy, diagnosis, and related-code detail. Data not available in the input is noted where appropriate.
Billing Code Overview
HCPCS Level II code M1338 describes follow-up assessments performed between 30 and 180 days after an index assessment for patients who did not demonstrate positive improvement or maintenance of functioning scores during the performance period. The code captures a follow-up outcome assessment indicating lack of expected functional progress or stability.
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Service type: Outcome-focused follow-up functional assessment
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Typical site of service: Ambulatory clinic, outpatient therapy setting, or home health follow-up visit where functional assessments are performed
Clinical & Coding Specifications
Clinical Context
A 68-year-old patient with chronic low back pain and progressive functional decline completes an initial standardized functional assessment (index assessment) by a physical therapist in an outpatient rehabilitation clinic. The index assessment documents baseline mobility, pain-related functional limitations, and validated outcome scores (for example, Oswestry Disability Index, PROMIS Physical Function). A follow-up assessment is scheduled between 30 and 180 days after the index assessment to measure treatment response and functional change. During the follow-up, the therapist repeats the same standardized outcome measures and documents that the patient did not demonstrate positive improvement or maintenance of functioning scores during the performance period. The clinical workflow includes verifying patient eligibility, obtaining informed consent for reassessment, performing standardized testing, comparing index and follow-up scores, documenting the lack of improvement or decline, and coding the encounter with HCPCS Level II code M1338 to indicate a 30–180 day follow-up without demonstrated improvement. Typical sites of service are outpatient rehabilitation clinics, hospital outpatient departments, and skilled nursing facilities where standardized functional outcome monitoring occurs. Common clinical scenarios include chronic musculoskeletal pain, post-surgical rehabilitation with stalled progress, and neurologic rehabilitation with plateaued function.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 |