13.4 Inpatient Transfer Policies, Cost Outliers & Short-Stay Rules

Inpatient Transfer Policies, Cost Outliers & Short-Stay Rules

AHIMA CCS Exam Focus: Transfer payment rules, cost outlier thresholds, and short-stay admission criteria are heavily tested on the CCS examination. Candidates must master the CMS Post-Acute Care Transfer (PACT) Policy, calculate graduated per-diem payment reductions when Length of Stay (LOS) is less than the Geometric Mean Length of Stay (GMLOS), identify qualifying post-acute discharge status codes, calculate High-Cost Outlier payments, and apply the Two-Midnight Rule (42 CFR § 412.3) to distinguish Part A inpatient admissions from Part B observation services.

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1. CMS Post-Acute Care Transfer (PACT) Policy

Under standard IPPS rules, a hospital receives the full MS-DRG prospective payment upon discharging a patient home, regardless of whether the patient stayed 2 days or 10 days. However, when an acute care hospital transfers a patient early in their stay to a post-acute care facility, Medicare would effectively be paying "twice" for the same episode of illness (once for the full acute DRG, and again for the post-acute stay under Medicare Part A SNF, IRF, or Home Health benefits).

To eliminate this double-payment incentive, Congress enacted Section 1886(d)(5)(J) of the Social Security Act, establishing the Post-Acute Care Transfer (PACT) Policy.

                         CMS PACT Policy Decision Tree
                               [Inpatient Discharge]
                                         │
                                         ▼
                  [Is MS-DRG on Qualifying PACT DRG List?]
                                 │               │
                         Yes ────┘               └───► No ➔ [Full MS-DRG Paid]
                          │
                          ▼
            [Is Patient Discharged to a Qualifying Post-Acute Setting?]
            (SNF [03], HHA w/in 3d [06], IRF [62], LTACH [63], Hospice [50/51])
                                 │               │
                         Yes ────┘               └───► No ➔ [Full MS-DRG Paid]
                          │
                          ▼
                  [Is Patient's Actual LOS < National GMLOS?]
                                 │               │
                         Yes ────┘               └───► No ➔ [Full MS-DRG Paid]
                          │
                          ▼
          [Apply Standard Per-Diem or Special-Pay Transfer Method]

Qualifying Post-Acute Discharge Settings (Discharge Status Codes):

• Discharge Status 03: Discharged/transferred to a Skilled Nursing Facility (SNF) with Medicare certification.
• Discharge Status 05: Discharged/transferred to a designated cancer hospital or children’s hospital.
• Discharge Status 06: Discharged/transferred to Home Health Care under an established plan of care providing skilled nursing/therapy services that begin within 3 calendar days of the discharge date.
• Discharge Status 50 / 51: Discharged/transferred to Hospice Care (routine home hospice or inpatient hospice facility).
• Discharge Status 62: Discharged/transferred to an Inpatient Rehabilitation Facility (IRF) or distinct-part rehabilitation unit.
• Discharge Status 63: Discharged/transferred to a Long-Term Acute Care Hospital (LTACH).
• Discharge Status 65: Discharged/transferred to a psychiatric hospital or distinct-part unit.

The PACT Qualifying Conditions:

For the PACT payment reduction to occur, ALL THREE of the following conditions must be met:

1. The assigned MS-DRG must appear on CMS’s annually updated qualifying Postacute MS-DRG list. A subset is separately identified for special-pay methodology.
2. The patient must be discharged to a qualifying post-acute setting under the applicable status-code and timing rules (including Status 03, 05, 06, 50, 51, 62, 63, or 65 as applicable).
3. The patient's actual Length of Stay (LOS) must be LESS than the national Geometric Mean Length of Stay (GMLOS) for that MS-DRG.

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2. Inpatient Transfer Payment Mechanics & Calculations

Type A: Acute-to-Acute Hospital Transfers (Discharge Status 02)

When an inpatient is transferred from one acute care IPPS hospital to another acute care IPPS hospital (Discharge Status 02):

• Transferring Hospital: Receives a graduated per-diem payment based on the number of days the patient was hospitalized.
• Receiving Hospital: Receives the full MS-DRG payment for the final encounter upon discharging the patient home.

The Standard Transfer Per-Diem Formula:

To account for the high fixed admission, triage, and diagnostic intake costs incurred on the first day of an acute hospitalization, CMS provides a double per-diem payment on Day 1 and single per-diem payments for each subsequent day:

$\text{Per-Diem Rate} = \frac{\text{Full MS-DRG Payment}}{\text{GMLOS}}$ $\text{Total Transfer Payment} = \text{Per-Diem Rate} \times (\text{Actual LOS} + 1)$

(Note: The total graduated per-diem payment is strictly capped at the full standard MS-DRG payment).

Step-by-Step PACT Calculation Example:

• Assigned MS-DRG: A hypothetical qualifying Postacute MS-DRG that uses the standard method (not a special-pay DRG)
• Full MS-DRG Base Payment: $12,000.00
• National GMLOS: 4.0 Days
• Encounter Course: Patient is discharged on Day 2 to a Skilled Nursing Facility (Discharge Status 03).

$\text{Per-Diem Rate} = \frac{\$12,000.00}{4.0} = \$3,000.00\text{ per day}$ $\text{Day 1 Payment (Double Per-Diem)} = \$3,000.00 \times 2 = \$6,000.00$ $\text{Day 2 Payment (Single Per-Diem)} = \$3,000.00 \times 1 = \$3,000.00$ $\mathbf{\text{Total Hospital Payment}} = \$6,000.00 + \$3,000.00 = \mathbf{\$9,000.00}$

(The hospital receives $9,000.00 instead of the full $12,000.00 payment because the patient was transferred early to a post-acute facility).

Special 50/50 PACT DRGs

For MS-DRGs designated on the current special-pay list, CMS uses an alternative 50/50 method: 50% of the full IPPS payment plus 50% of the otherwise applicable standard transfer payment, capped at the full payment. Because qualifying and special-pay designations are updated, verify the applicable fiscal-year list before calculating a real claim.

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3. Inpatient High-Cost Outlier Payments

To protect hospitals from catastrophic financial losses when treating exceptionally complex patients whose care requires extreme, uncharacteristic resource consumption, CMS provides supplemental High-Cost Outlier Payments under Section 1886(d)(5)(A) of the Social Security Act.

                      High-Cost Outlier Calculation Flow
  [Total Billed Charges] × [Hospital Cost-to-Charge Ratio (CCR)]
                                │
                                ▼
                     [Estimated Facility Cost]
                                │
                                ▼
      [Is Estimated Cost > (Standard MS-DRG Payment + Fixed-Loss Threshold)?]
                                │
                        Yes ────┘
                         │
                         ▼
   [Outlier Payment = 80% × (Estimated Facility Cost - Outlier Cost Threshold)]

Mathematical Formulation of High-Cost Outliers:

1. Estimated Facility Cost Calculation: $\text{Estimated Cost} = \text{Total Inpatient Billed Charges} \times \text{Hospital's Operating Cost-to-Charge Ratio (CCR)}$

2. Outlier Cost Threshold Calculation: $\text{Outlier Cost Threshold} = \text{Standard MS-DRG Payment} + \text{Annual CMS Fixed-Loss Cost Threshold}$

3. Marginal Outlier Payment Formula:

   • If Estimated Cost > Outlier Cost Threshold, CMS pays 80% of the marginal cost excess (or 90% for designated burn MS-DRGs 927–935): $\text{Outlier Supplemental Payment} = 0.80 \times (\text{Estimated Cost} - \text{Outlier Cost Threshold})$ $\mathbf{\text{Total Final Payment}} = \text{Standard MS-DRG Payment} + \text{Outlier Supplemental Payment}$

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4. The Two-Midnight Rule & Short-Stay Admission Integrity

Established in the FY 2014 IPPS Final Rule (42 CFR § 412.3), the Two-Midnight Rule governs whether an inpatient hospital admission is reasonable and necessary for Medicare Part A reimbursement, distinguishing inpatient admissions from outpatient observation services under Medicare Part B.

                         The Two-Midnight Benchmark
  Expected medically necessary care spanning 2+ midnights
       -> generally appropriate for Part A when documented

  Expected stay under 2 midnights
       -> generally outpatient, but Part A may be appropriate
          case by case when documented complex medical factors support it

  Separate current exceptions/status rules
       -> remaining Inpatient-Only procedures and newly initiated
          mechanical ventilation; verify the current CMS files

Critical Principles of the Two-Midnight Rule:

1. The Clock Starts in the Emergency Department: When calculating the expected two midnights, the time begins when the patient starts receiving active outpatient services (e.g., initial triage, emergency department care, observation care), not when the formal formal inpatient admission order is signed.
2. Physician Expectation & Documentation: The admitting order must be substantiated by contemporaneous physician documentation demonstrating a reasonable expectation that the patient required active inpatient hospital care spanning across two midnights.
3. Current Exceptions and Annual Status: Procedures still assigned to the Inpatient-Only list and newly initiated mechanical ventilation are exceptions to the general benchmark. CMS began a three-year phaseout of the IPO list in CY 2026, so a procedure’s status must be verified for the date of service. Procedures removed from the list are not automatically inpatient.
4. Audit Enforcement: Effective September 1, 2025, Medicare Administrative Contractors conduct short-stay patient-status reviews and provider education through Targeted Probe and Educate. A stay under two midnights can still qualify when a supported two-midnight expectation ended early because of an unforeseen event, or when documented case-specific medical factors support inpatient care.