IRF-PAI Manual Version 4.2 — FY 2025

Inpatient Rehabilitation Facility Patient Assessment Instrument

Document Scope

The IRF-PAI is the standardized assessment instrument used to collect patient data for quality measure calculation and payment determination under the IRF Prospective Payment System (PPS) and Quality Reporting Program (QRP). 1
Effective Date: October 1, 2024 for all patients discharged on or after this date. 1

🔑 Core Framework: Dual Payment/Reporting Systems

IRF PPS vs. IRF QRP: Two Parallel Tracks

┌─────────────────────────────────────────┐
│ IRF PROSPECTIVE PAYMENT SYSTEM (PPS)    │
├─────────────────────────────────────────┤
│ • Determines CMG (Case-Mix Group) payment │
│ • Based on:                              │
│   - Functional status (GG section)       │
│   - Comorbidities (Item I: Active Diagnoses) │
│   - Age, prior functioning, cognitive status │
│ • Payment = Base rate × CMG weight × adjustments │
│ • Base rate FY2025: $18,907 [[42]]        │
└─────────────────────────────────────────┘

┌─────────────────────────────────────────┐
│ IRF QUALITY REPORTING PROGRAM (QRP)     │
├─────────────────────────────────────────┤
│ • Measures: Pressure ulcers, falls, functional improvement │
│ • Data submission via iQIES or NHSN     │
│ • Two completeness thresholds:          │
│   - 95% for IRF-PAI submitted measures  │
│   - 100% for NHSN-reported measures     │
│ • Failure = 2% reduction to AIF [[3]]    │
└─────────────────────────────────────────┘

Critical Distinction

IRF-PAI comorbidity sequencing differs from acute care MS-DRG logic. Only comorbidities sequenced in the first 10 positions of Item I (Active Diagnoses) can impact CMG payment tier assignment. 22

📋 IRF-PAI v4.2 Section Overview (Table 2-1)

Section	Title	Primary Coding Focus	CC/MCC Relevance
A	Administrative Information	Payer, demographics, transportation	Indirect (affects data completeness)
B	Hearing, Speech, Vision	Sensory deficits impacting therapy	May support functional limitation documentation
C	Cognitive Patterns	BIMS, delirium screening	Cognitive impairment may qualify as comorbidity tier
D	Mood	PHQ-2/9, social isolation	Depression/anxiety may impact therapy participation
GG	Functional Abilities	Self-care, mobility, prior function	PRIMARY DRIVER of CMG assignment
H	Bladder/Bowel	Continence status	Neurogenic bladder/bowel may qualify as comorbidity
I	Active Diagnoses	ICD-10-CM codes influencing function or pressure ulcer risk	CORE SECTION for comorbidity tier assignment
J	Health Conditions	Pain, falls history, prior surgery	Pain severity may support therapy intensity documentation
K	Swallowing/Nutrition	Nutritional approaches	Malnutrition codes may qualify for comorbidity tier
M	Skin Conditions	Pressure ulcer staging	Stage 3/4 ulcers = MCC; impacts both payment & quality metrics
N	Medications	High-risk drug classes	Anticoagulants, psychotropics may support complexity documentation
O	Special Treatments	Dialysis, ventilation, IV meds	May support medical complexity for CMG assignment
Z	Assessment Administration	Signatures, dates	Compliance requirement

🎯 Section I: Active Diagnoses — Comorbidity Coding Rules

Purpose & Intent 3

“The items in this section are intended to indicate the presence of active diagnoses that influence a patient’s functional outcomes or increase a patient’s risk for the development or worsening of pressure ulcer(s).”

Comorbidity Tier Payment Logic

graph LR
    A[Item I: Active Diagnoses] --> B{Code appears on<br>Comorbidity List?}
    B -->|No | C[No payment impact]
    B -->|Yes | D{Sequenced in<br>first 10 positions?}
    D -->|No | C
    D -->|Yes | E{Assigned to Tier?}
    E -->|Tier 1 | F[+ Highest CMG adjustment]
    E -->|Tier 2 | G[+ Moderate CMG adjustment]
    E -->|Tier 3 | H[+ Lower CMG adjustment]

FY 2025 Comorbidity Tier Examples 2750

Tier	Clinical Examples	Representative ICD-10-CM Codes	Payment Impact
Tier 1 (Highest)	• Metastatic cancer • End-stage renal disease on dialysis • Severe malnutrition • Advanced COPD with chronic respiratory failure	C79.51, N18.6, E43, J44.1 + J96.10	+ $2, 500 -$ 4,000 to base CMG
Tier 2	• Parkinson disease with complications • Major depressive disorder, recurrent severe • Rheumatoid arthritis with systemic involvement	G20, F33.2, M05.9	+ $1, 200 -$ 2,400 to base CMG
Tier 3	• Hypertension with heart/kidney disease • Type 2 diabetes with complications • Osteoporosis with current pathologic fracture	I13.9, E11.40, M80.08XA	+ $400 -$ 1,100 to base CMG

Sequencing is Critical

A comorbidity assigned to a payment tier must be sequenced within the first 10 comorbidities on the IRF-PAI to be reported and impact reimbursement. 22 Always place highest-tier qualifying conditions first.

Documentation Requirements for Item I 3

✅ MUST DOCUMENT:
• Diagnosis is ACTIVE (not historical) during the IRF stay
• Diagnosis influences functional outcomes OR increases pressure ulcer risk
• ICD-10-CM code is specific (laterality, stage, severity as required)
• Provider has documented the diagnosis in the medical record
 
❌ DO NOT CODE:
• Historical conditions with no current impact on care
• Diagnoses ruled out after study
• Signs/symptoms when definitive diagnosis is established
• Conditions not supported by clinical indicators in the record

⚙️ The 60% Rule & Presumptive Compliance

Regulatory Requirement 5355

At least 60% of an IRF’s patients must have one or more conditions from the presumptive compliance list to maintain Medicare certification as an IRF.

Presumptive Compliance List Highlights 5051

// Neurologic Conditions
G81.90  Hemiplegia, unspecified
G82.50  Tetraplegia, unspecified
G35     Multiple sclerosis
G20     Parkinson disease
I69.351 Unspecified monoplegia of lower limb following cerebral infarction
 
// Orthopedic/Musculoskeletal
M84.451A Pathologic fracture, right femur, initial encounter
M16.11  Unilateral primary osteoarthritis, right hip
T84.50XA Infection and inflammatory reaction due to unspecified joint prosthesis
 
// Other Qualifying Conditions
E11.40  Type 2 diabetes mellitus with diabetic neuropathy, unspecified
I50.9   Heart failure, unspecified
J44.9   Chronic obstructive pulmonary disease, unspecified

Two Methods for 60% Rule Determination 54

Method	How It Works	Data Source
Presumptive Methodology	Counts patients with ≥1 diagnosis code from the presumptive list on the IRF-PAI	IRF-PAI Item I (Active Diagnoses)
Medical Review Methodology	Clinical review of medical records to determine if patient required intensive rehab services regardless of diagnosis code	Full medical record audit

Audit Risk

MACs (Medicare Administrative Contractors) conduct compliance reviews. Facilities with presumptive compliance near 60% threshold should ensure accurate, specific coding of qualifying conditions in Item I. 5859

📅 Assessment & Submission Timeline (v4.2)

Admission Assessment Schedule 3

Milestone	Timing Requirement	Notes
Assessment Reference Date (Item 13)	Day 3 of stay*	*If stay <3 days, use last day of stay
IRF-PAI Completed By	Day 4 of stay	All required items encoded
Data Encoded By	Day 10 of stay	Entered into submission software
Data Transmitted By	With discharge data (see below)	Admission + discharge sent together

Discharge Assessment Schedule 3

Milestone	Timing Requirement	Notes
Discharge Date	Day patient leaves IRF	Counts as Day 1 of 27-day window
Assessment Reference Date	Discharge date	Typically same as discharge date
IRF-PAI Completed By	Discharge date + 4 days	e.g., Discharge 10/16 → Complete by 10/20
Data Encoded By	Discharge date + 10 days	e.g., Discharge 10/16 → Encode by 10/26
Data Transmitted By	Discharge date + 16 days	e.g., Discharge 10/16 → Transmit by 11/1
Late Transmission Threshold	Discharge date + 27 days	After this = late submission penalty

Short Stays (<3 Calendar Days)

For stays less than 3 calendar days:
• Complete admission items only
• Admission Assessment Reference Date = last day of stay
• Discharge assessment not required 3

🔍 High-Yield Coding Scenarios for PMR Specialties

Scenario 1: Stroke Rehabilitation with Comorbidities

Patient admitted for inpatient rehab post-left MCA stroke.
Documented conditions:
• Right hemiplegia (G81.91) — Principal reason for rehab
• Aphasia (R47.01) — Impacts therapy participation
• Type 2 diabetes with CKD stage 4 (E11.22 + N18.4) — Tier 3 comorbidity
• Hypertensive heart disease (I11.9) — Tier 3 comorbidity
• History of MI (Z87.891) — Historical, does NOT qualify
 
IRF-PAI Item I Sequencing:
1. G81.91 (principal functional diagnosis)
2. R47.01 (impacts therapy)
3. E11.22 (Tier 3 comorbidity) ← Must be in first 10
4. N18.4 (supports E11.22)
5. I11.9 (Tier 3 comorbidity) ← Must be in first 10
 
✅ Payment Impact: Two Tier 3 comorbidities in first 10 positions = moderate CMG adjustment

Scenario 2: Spinal Cord Injury with Complications

Patient with T6 complete paraplegia admitted for rehab.
Complications during stay:
• Stage 3 sacral pressure ulcer developed day 5 (L89.153) — POA=N, MCC
• UTI with E. coli (N39.0 + B96.20) — Treated with IV antibiotics
• Autonomic dysreflexia episode (G90.4) — Required emergency intervention
 
IRF-PAI Coding:
• Item I (Active Diagnoses): 
  - G82.20 (Paraplegia, complete) — Principal
  - L89.153 (Pressure ulcer stage 3, sacrum) — POA=N, impacts care
  - N39.0 (UTI) — Treated, increased nursing care
• Item M (Skin Conditions): 
  - M0350 = 1 (Pressure ulcer present at discharge)
  - M0360 = 3 (Stage 3)
• Item J (Health Conditions): 
  - J1900 = 1 (Falls since admission) if applicable
 
✅ Quality Impact: Stage 3 pressure ulcer (POA=N) triggers quality measure review
✅ Payment Impact: UTI and pressure ulcer may support higher CMG if impacting function

Scenario 3: Complex Orthopedic Rehab

Patient post-bilateral TKA with multiple comorbidities.
Key documentation:
• Severe protein-calorie malnutrition (E43) — Tier 1 comorbidity
• COPD with acute exacerbation (J44.1) — Tier 1 comorbidity  
• Rheumatoid arthritis with lung involvement (M05.9 + J99) — Tier 2
• Chronic pain syndrome (G89.29) — Supports therapy complexity
 
IRF-PAI Strategy:
1. Sequence E43 and J44.1 in FIRST TWO positions of Item I
2. Ensure provider documentation explicitly states "severe" malnutrition and "acute exacerbation" COPD
3. Link rheumatoid arthritis to functional limitations in therapy notes
4. Document pain severity and impact on therapy participation in progress notes
 
✅ Payment Impact: Two Tier 1 comorbidities = highest possible CMG adjustment for non-neurologic cases

⚠️ Common IRF-PAI Coding Pitfalls & Solutions

Pitfall	Risk	Solution
Comorbidity sequenced > position 10	Loss of CMG payment adjustment	Audit Item I sequencing; place qualifying comorbidities first 22
Using unspecified codes when specificity exists	Denied presumptive compliance; lower CMG	Train providers on laterality/stage documentation; query for specificity
Coding historical conditions as active	Audit findings; potential overpayment	Apply UHDDS guidelines: only code conditions affecting current stay
POA indicator errors on complications	HAC payment adjustments; quality metric penalties	Review POA logic: complications developing during stay = POA=N
Incomplete GG functional scoring	Incorrect CMG assignment; quality measure errors	Use standardized assessment tools; document baseline vs. discharge scores
Missing pressure ulcer staging	Inaccurate quality reporting; missed MCC	Ensure wound care documentation includes stage, location, laterality

📚 Official Resources

Bottom Line

IRF-PAI v4.2 coding requires mastery of: (1) functional assessment logic (GG section drives CMG), (2) comorbidity tier rules (Item I sequencing critical), (3) 60% rule compliance (presumptive list accuracy), and (4) quality measure alignment (pressure ulcers, falls, functional improvement). Always validate against the official CMS manual and query providers when documentation lacks specificity for tier assignment or presumptive compliance.

Last synced: $(date)
Next update: IRF-PAI v4.3 expected October 2025 (monitor CMS IRF PPS website)

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IRF-PAI Manual v4.2

IRF-PAI Manual Version 4.2 — FY 2025

🔑 Core Framework: Dual Payment/Reporting Systems

IRF PPS vs. IRF QRP: Two Parallel Tracks

📋 IRF-PAI v4.2 Section Overview (Table 2-1)

🎯 Section I: Active Diagnoses — Comorbidity Coding Rules

Purpose & Intent 3

Comorbidity Tier Payment Logic

FY 2025 Comorbidity Tier Examples 2750

Documentation Requirements for Item I 3

⚙️ The 60% Rule & Presumptive Compliance

Regulatory Requirement 5355

Presumptive Compliance List Highlights 5051

Two Methods for 60% Rule Determination 54

📅 Assessment & Submission Timeline (v4.2)

Admission Assessment Schedule 3

Discharge Assessment Schedule 3

🔍 High-Yield Coding Scenarios for PMR Specialties

Scenario 1: Stroke Rehabilitation with Comorbidities

Scenario 2: Spinal Cord Injury with Complications

Scenario 3: Complex Orthopedic Rehab

⚠️ Common IRF-PAI Coding Pitfalls & Solutions

🔗 Related Vault Notes

📚 Official Resources

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