MAC Audit Trigger Case Studies
Learn from real-world scenarios: 6 cases that WILL trigger MAC audits and 6 cases that WON'T
RED FLAG Cases
These scenarios WILL trigger MAC audit scrutiny
Scenario:
A 72-year-old patient admitted with left-sided stroke (I63.9). IRF-PAI shows admission FIM motor score of 65 (indicating moderate independence), but physician admission note states "patient unable to sit unsupported, requires maximal assistance for all transfers, total dependence for ADLs."
Why This Triggers Audit:
- • FIM score of 65 suggests patient can perform many activities with supervision only
- • Medical record clearly documents total dependence and maximal assistance needs
- • Discrepancy suggests upcoding to achieve higher CMG payment
- • MAC will request medical records to verify FIM accuracy
Prevention Strategy:
FIM scores MUST match functional abilities documented in admission H&P, therapy evaluations, and nursing assessments. Review all clinical documentation before finalizing IRF-PAI.
Scenario:
A 68-year-old patient admitted with hip fracture (S72.001A). IRF-PAI lists Tier 3 comorbidities including CHF (I50.9), COPD (J44.9), diabetes with complications (E11.65), and chronic kidney disease Stage 4 (N18.4). However, admission H&P only mentions "history of hypertension" with no active treatment or monitoring for the claimed comorbidities during IRF stay.
Why This Triggers Audit:
- • Tier 3 assignment significantly increases CMG payment
- • Medical record lacks evidence of active treatment for claimed comorbidities
- • No physician orders for CHF management, COPD medications, or CKD monitoring
- • Suggests comorbidity inflation to maximize reimbursement
Prevention Strategy:
Only code comorbidities that are ACTIVE, DOCUMENTED, and TREATED during the IRF stay. Verify physician orders, medications, labs, and nursing interventions support each claimed comorbidity.
Scenario:
Oasis Point's quarterly compliance report shows 58.7% of patients fall into CMS-13 qualifying conditions. Upon MAC review, several patients coded as "neurological disorders" (RIC 01.4) actually have primary diagnoses of general debility (R53.81) or failure to thrive (R62.7), which do NOT qualify for the 60% Rule.
Why This Triggers Audit:
- • Facility is below 60% compliance threshold (58.7% vs required 60%)
- • Pattern of miscoding non-qualifying diagnoses as neurological disorders
- • Suggests systematic attempt to inflate 60% Rule compliance
- • MAC will audit ALL admissions for correct diagnosis classification
Prevention Strategy:
Maintain 60% Rule compliance at 65-70% minimum to allow for margin of error. Never code general debility or deconditioning as neurological disorders. Track compliance daily and adjust admissions proactively.
Scenario:
MAC data shows Oasis Point submitted 23 IRF-PAI admission assessments beyond the 3-day window in Q4 2024. Additionally, 15 discharge assessments were submitted 3-5 days after discharge date. Several assessments show evidence of backdating to appear compliant.
Why This Triggers Audit:
- • Late submissions suggest incomplete or inaccurate initial assessments
- • Backdating is considered fraudulent documentation
- • Pattern indicates systemic workflow failures and lack of oversight
- • MAC questions reliability of ALL facility IRF-PAI data
Prevention Strategy:
Implement daily IRF-PAI completion tracking with alerts at 48 hours post-admission. Never backdate assessments. If late submission is unavoidable, document reason and corrective action plan.
Scenario:
A 75-year-old patient admitted with knee replacement (RIC 08.5). Admission FIM motor: 62. Discharged after 4 days. Discharge FIM motor: 64 (gain of only 2 points). Medical record shows patient participated in therapy only 2 days due to "patient refusal" and "excessive fatigue." No documented intensive rehabilitation.
Why This Triggers Audit:
- • IRF requires intensive rehabilitation (3 hours/day minimum)
- • Minimal FIM gain (2 points) suggests patient didn't benefit from IRF level of care
- • Short stay with therapy refusal indicates inappropriate admission
- • Patient likely should have been admitted to SNF, not IRF
Prevention Strategy:
Screen patients for IRF appropriateness BEFORE admission. Verify rehabilitation potential, medical stability, and ability to tolerate 3 hours of therapy daily. Document preadmission screening results.
Scenario:
Patient transferred from acute hospital with discharge diagnosis of "generalized weakness, deconditioning" (R53.81). IRF admission IRF-PAI lists primary diagnosis as "stroke with hemiplegia" (I69.351) to qualify for 60% Rule. However, acute hospital records show NO stroke, NO neurological deficits, and normal brain CT/MRI.
Why This Triggers Audit:
- • IRF diagnosis directly contradicts acute hospital documentation
- • No medical evidence supports stroke diagnosis
- • Clear attempt to misrepresent diagnosis for 60% Rule qualification
- • Constitutes fraudulent coding and billing
Prevention Strategy:
IRF diagnosis MUST match acute hospital discharge diagnosis and be supported by medical evidence. Never change diagnosis to qualify for 60% Rule. If patient doesn't meet criteria, admit to SNF instead.
GREEN FLAG Cases
These scenarios demonstrate compliant IRF-PAI practices
Scenario:
A 70-year-old patient admitted with right-sided stroke (I63.411). IRF-PAI shows admission FIM motor score of 38. Physician H&P documents "left hemiparesis, requires moderate assistance for transfers, maximal assistance for ADLs, unable to ambulate independently." PT evaluation confirms "FIM transfer score: 3, FIM ambulation score: 2." Nursing assessment states "patient requires 2-person assist for bed mobility."
Why This Is Compliant:
- ✓ FIM score of 38 accurately reflects documented functional limitations
- ✓ All disciplines (MD, PT, RN) document consistent functional status
- ✓ Specific FIM item scores match clinical observations
- ✓ No discrepancies between IRF-PAI and medical record
Best Practice Demonstrated:
Interdisciplinary team collaborates to ensure FIM scores accurately reflect patient's true functional abilities. IRF-PAI Coordinator reviews all clinical documentation before finalizing assessment.
Scenario:
A 73-year-old patient admitted with hip fracture (S72.001A). IRF-PAI lists Tier 2 comorbidities: diabetes mellitus Type 2 (E11.9) and hypertension (I10). Medical record shows: daily blood glucose monitoring with insulin administration per sliding scale, BP checks TID with metoprolol 50mg BID, physician progress notes document "continue diabetes and HTN management," and nursing flow sheets show consistent monitoring and interventions.
Why This Is Compliant:
- ✓ Comorbidities are ACTIVE with ongoing treatment during IRF stay
- ✓ Physician orders support each claimed comorbidity
- ✓ Nursing documentation shows daily monitoring and interventions
- ✓ Medications administered and documented throughout stay
Best Practice Demonstrated:
Only code comorbidities with clear evidence of active treatment. Verify physician orders, medication administration records, lab results, and nursing interventions support tier assignment.
Scenario:
Oasis Point's quarterly compliance report shows 68.3% of patients fall into CMS-13 qualifying conditions. Internal audit confirms all stroke diagnoses have documented neurological deficits, all hip fractures have radiographic evidence, and all neurological disorders have supporting diagnostic testing (MRI, EMG, etc.). No questionable diagnoses identified.
Why This Is Compliant:
- ✓ Facility exceeds 60% threshold with comfortable 8.3% buffer
- ✓ All qualifying diagnoses supported by medical evidence
- ✓ Internal audit process validates diagnosis accuracy
- ✓ No pattern of questionable or inflated diagnosis coding
Best Practice Demonstrated:
Maintain 60% Rule compliance at 65-70% to allow margin for error. Conduct monthly internal audits to verify diagnosis accuracy. Track compliance daily and adjust admission decisions proactively.
Scenario:
Oasis Point submitted all Q4 2024 IRF-PAI assessments within required timeframes: 100% of admission assessments completed within 3 days, 100% of discharge assessments completed within 24 hours of discharge. Electronic tracking system shows timestamp audit trail. IRF-PAI Coordinator conducts daily review of pending assessments and sends alerts at 48-hour mark.
Why This Is Compliant:
- ✓ Perfect on-time submission record demonstrates strong workflow
- ✓ Electronic tracking provides audit trail and accountability
- ✓ Proactive alert system prevents late submissions
- ✓ Dedicated IRF-PAI Coordinator ensures quality oversight
Best Practice Demonstrated:
Implement robust tracking system with automated alerts. Assign dedicated IRF-PAI Coordinator with daily oversight responsibility. Never backdate assessments—address workflow issues instead.
Scenario:
A 72-year-old patient admitted with bilateral knee replacement (RIC 08.5). Admission FIM motor: 48. Length of stay: 12 days. Discharge FIM motor: 74 (gain of 26 points). Therapy documentation shows patient participated in 3+ hours of therapy daily, progressed from wheelchair level to independent ambulation with walker, and achieved all rehabilitation goals. Preadmission screening documented rehabilitation potential and medical stability.
Why This Is Compliant:
- ✓ Significant FIM gain (26 points) demonstrates benefit from IRF care
- ✓ Patient participated in intensive rehabilitation (3+ hours daily)
- ✓ Appropriate length of stay with documented functional progress
- ✓ Preadmission screening supports IRF-level care appropriateness
Best Practice Demonstrated:
Conduct thorough preadmission screening to verify IRF appropriateness. Document rehabilitation potential, therapy tolerance, and expected functional gains. Track FIM progress throughout stay to demonstrate benefit.
Scenario:
Patient transferred from acute hospital with discharge diagnosis of "ischemic stroke, left MCA territory, with right hemiparesis" (I63.512). IRF admission IRF-PAI lists identical primary diagnosis (I63.512). Acute hospital records include brain MRI showing left MCA infarct, neurology consultation confirming stroke, and discharge summary documenting right-sided weakness. IRF admission H&P confirms ongoing right hemiparesis requiring intensive rehabilitation.
Why This Is Compliant:
- ✓ IRF diagnosis exactly matches acute hospital discharge diagnosis
- ✓ Medical evidence (MRI, neurology consult) supports diagnosis
- ✓ Clinical presentation consistent across care continuum
- ✓ No diagnosis manipulation to qualify for 60% Rule
Best Practice Demonstrated:
Obtain complete acute hospital records before admission. Verify IRF diagnosis matches acute discharge diagnosis and is supported by diagnostic testing. Never change diagnosis to meet 60% Rule requirements.
Audit Triggers to Avoid
- • FIM scores inconsistent with medical documentation
- • Comorbidities not actively treated or documented
- • 60% Rule compliance below 60% or near threshold
- • Late IRF-PAI submissions or backdating
- • Short stays with minimal functional gain
- • Diagnosis changes from acute hospital records
Compliance Best Practices
- • Ensure FIM scores match all clinical documentation
- • Code only active, treated comorbidities with evidence
- • Maintain 65-70% compliance with 60% Rule
- • Submit all IRF-PAI assessments on time
- • Document significant functional gains and therapy participation
- • Maintain diagnosis consistency across care continuum