M1141 HCPCS: Reimbursement & Policy Benchmarks | OpenPayer

Summary & Overview

HCPCS M1141: Functional Status Not Measured by OKS or KOOS, JR. at 1 Year

HCPCS Level II code M1141 documents that knee-specific functional status measures—the Oxford Knee Score (OKS) or the KOOS, JR.—were not obtained at the one-year postoperative interval (9 to 15 months). Nationally, this code flags missing standardized patient-reported outcome data for joint replacement follow-up, which can affect quality measurement, registry reporting, and program compliance. Major payers commonly considered in analyses include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the code’s clinical context, typical service setting, and implications for postoperative outcome tracking. The publication provides benchmark-oriented information on how the code is used in claims, discussion of reporting considerations, and context for quality measurement and registry participation. Where available, payer coverage patterns and common modifiers used with related services are summarized. Data not available in the input are noted explicitly.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareM1141HCPCS Level IIknee replacementpatient-reported outcomespostoperative follow-upfunctional statusorthopedicsquality measurementoutcome measures

Billing Code Overview

HCPCS Level II code M1141 indicates that functional status was not measured by the Oxford Knee Score (OKS) or the Knee injury and Osteoarthritis Outcome Score Joint Replacement (KOOS, JR.) at one year (9 to 15 months) postoperatively. This code documents the absence of those standardized knee-specific patient-reported outcome measures during the specified postoperative interval.

Service type: Outcome measurement / postoperative functional assessment documentation

Typical site of service: Orthopedic clinic or postoperative follow-up setting

Data not available in the input for associated taxonomies, ICD-10 diagnoses, and related codes.

Clinical & Coding Specifications

Clinical Context

A 68-year-old patient presents for routine one-year postoperative follow-up (9–15 months) after primary total knee arthroplasty. During the clinic visit the surgeon documents wound healing, range of motion, strength, pain level, and radiographic review. The patient is ambulatory with a cane and reports intermittent anterior knee pain. Functional outcome questionnaires such as the Oxford Knee Score (OKS) or the Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR.) were not completed during this visit due to patient fatigue and scheduling constraints. The clinical workflow includes: pre-visit chart review, focused physical exam, plain radiographs if indicated, documentation of patient-reported outcomes when available, and coding/billing for the encounter. Billing uses HCPCS Level II code M1141 to indicate that the one-year postoperative functional status was not measured by OKS or KOOS, JR. (window 9–15 months). Typical sites of service are the orthopaedic clinic, hospital outpatient department, or ambulatory surgery center during postoperative surveillance appointments.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when work required is substantially greater than typical for a postoperative clinic visit due to complexity (document justification).

HCPCS Level II M1139: Ongoing Care Not Indicated, Early Self-Discharge

HCPCS-M1123-NON-INDICATED-ONGOING-CARE-HOME-PROGRAM-REFERRAL

HCPCS M1123: Non‑indicated Ongoing Care — Home Program/Referral

HCPCS-M1122-DEGENERATIVE-NEUROLOGICAL-CONDITION-DOCUMENTATION

HCPCS M1122: Degenerative Neurological Condition Documentation

HCPCS-M1126-EPISODE-START-DOCUMENTATION

HCPCS M1126: Start of Episode of Care, Documented in Record

HCPCS-M1131-DEGENERATIVE-NEUROLOGICAL-CONDITION-DOCUMENTATION

HCPCS Level II M1131: Degenerative Neurological Condition Documentation

HCPCS-M1116-START-EPISODE-OF-CARE-DOCUMENTATION

HCPCS Level II M1116: Start of Episode of Care Documentation

HCPCS-M1135-EPISODE-OF-CARE-START-DOCUMENTATION

HCPCS M1135: Start of Episode of Care Documentation

HCPCS-M1138-SHORT-TERM-CONSULTATION-REFERRAL-ONLY

HCPCS M1138: Short-Term Consultation or Referral, 1-2 Visits

HCPCS-M1117-DEGENERATIVE-NEUROLOGICAL-DIAGNOSIS-DOCUMENTATION

HCPCS M1117: Documentation of Degenerative Neurological Diagnosis

HCPCS-M1108-HOME-PROGRAM-REFERRAL-CONSULTATION-ONLY

HCPCS M1108: Ongoing Care Not Clinically Indicated; Home Program/Referral/Consult

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Taxonomy Code	Specialty	Notes
207X00000X	Orthopaedic Surgery	Primary specialty performing total knee arthroplasty and postoperative follow-up.
207L00000X	Pain Medicine (Anesthesiology)	May be involved for complex pain management or perioperative anesthesia issues.
208000000X	Family Medicine	Often provides routine postoperative surveillance in primary care settings.
363L00000X	Physical Therapy	Provides rehabilitation assessments and functional outcome measurements like OKS/KOOS, JR.
2086S0122X	Physician Assistant (PA)	Assists with postoperative visits and documentation; may perform portions of follow-up care.

ICD-10 Code	Description	Clinical Relevance
Data not available in the input.	Data not available in the input.	Data not available in the input.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`27130`	Total hip arthroplasty or total hip replacement (used here for comparison across joint arthroplasty workflows)	Not directly related to knee function measurement but commonly paired in arthroplasty program reporting and postoperative outcome tracking.
`27447`	Arthroplasty, knee, condyle and plateau; medial and lateral compartments with or without patellar resurfacing (total knee arthroplasty)	Primary procedure whose one-year functional outcomes would be tracked by OKS or KOOS, JR.; `M1141` documents when those scores were not obtained.
`99214`	Office or other outpatient visit for the evaluation and management of an established patient, moderate complexity	Common outpatient visit code for postoperative 9–15 month follow-up when functional scores are not captured.
`73721`	Radiologic exam, knee, 2 views, standing or weight-bearing (radiographic imaging)	Often performed during postoperative evaluation; supports clinical assessment when outcome scores are missing.
`97001`	Physical therapy evaluation	Performed by physical therapy to assess function and may include administration of OKS/KOOS, JR.; absence of these scores is captured by `M1141`.

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