CurrentFidelis CarePolicy CP.FC.28

Short Inpatient Hospital Stay

Medical necessity criteria for inpatient hospital stays shorter than three midnights (first and second days), excluding behavioral health and obstetrical delivery admissions; applies to Fidelis Care HBX product lines and affiliated health plans.

Policy Summary

PayerFidelis Care

PolicyShort Inpatient Hospital Stay

Policy CodePolicy CP.FC.28

Change TypeNo material change

Effective Date

Next Review Date

Key ActionDocument that short inpatient stays (<3 midnights) meet one of criteria I.A–I.F to support medical necessity and prior authorization where required.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

less than three midnightsstays defined as short inpatient hospital stay

first and second daysdays the policy specifically governs

3 midnightstransfer threshold

CMS listinpatient-only procedures

Coverage Criteria for Short Inpatient Hospital Stays

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I.A: Admission is for a procedure on the current CMS Inpatient Only List

See addendum/links to Inpatient Only List

I.B: Admission to a licensed intensive care unit or licensed Neonatal Intermediate Care Unit, and considered medically necessary per a nationally-recognized clinical decision support tool in use by the applicable plan

Must be supported by the plan's clinical decision support tool

I.C: Unexpected death during the admission

I.D: Departure against medical advice from a medically necessary (per a nationally-recognized clinical decision support tool) inpatient stay

I.E: Transferred from another facility, with a medically necessary (per a nationally-recognized clinical decision support tool) total length of inpatient stay of three midnights or more3 midnights or more

Transfer must be from an inpatient stay

I.F: Election of hospice care in lieu of continued treatment in hospital

Days 3+ medical necessity

Stance for stays lasting three midnights and beyond:

II: Inpatient hospital stays lasting three midnights and beyond are medically necessary when supported by nationally-recognized clinical decision support tools in use by the plan>= 3 midnights

See plan-specific clinical decision support tools

An inpatient stay of less than three midnights (first and second days) that does not meet any one of the listed indications (I.A–I.F) is not supported as medically necessary under this policy. Providers should ensure that one of the specified short-stay indications—such as a procedure on the CMS Inpatient Only List, ICU/Neonatal Intermediate admission supported by the plan’s clinical decision support tool, unexpected death during the admission, departure against medical advice from a medically necessary inpatient stay, transfer from another facility with a total inpatient stay of three midnights or more, or election of hospice care—is documented to support an inpatient level of care for stays under three midnights.

Coding and Thresholds

Referenced coding systemsmixed

CPT (referenced)

Current Procedural Terminology codes referenced for coding implications; specific CPT codes not listed in policy.

Inpatient-only proceduresneutralCovered

CMS Inpatient Only List (2025)

Procedures on CMS Inpatient Only List require inpatient setting for Medicare; list referenced in policy (link to addendum).

inv-07: Short stay threshold — less than three midnights

ThresholdLess than three midnights

Applies toInpatient stays — first and second days (short inpatient hospital stay)

Usage in policyDefines which inpatient stays require one of criteria I.A–I.F to be medically necessary

Provider Actions, Prior Authorization, and Documentation

Prior Authorization

Prior authorization / medical necessity for short inpatient stays

Inpatient level of care for hospital stays of less than three midnights is medically necessary only when one of criteria I.A–I.F is met (see policy for full list of indications, including CMS Inpatient Only procedures, ICU/Neonatal Intermediate admission supported by the plan's clinical decision support tool, unexpected death, departure against medical advice from a medically necessary stay, transfer from an inpatient stay with a total length of three midnights or more, or election of hospice). Days three and beyond are governed by nationally-recognized clinical decision support tools used by the applicable plan.

Step Therapy

Step therapy

There are no step therapy requirements specified in this policy.

Documentation Required

Coding and documentation guidance

Providers must reference the most up-to-date professional coding guidance prior to claim submission; CPT and other codes included in this policy are informational only and their inclusion or exclusion does not guarantee coverage.

Denial Risk

Denial risk for unsupported short stays

Admissions for less than three midnights that do not meet any of the listed indications (I.A–I.F) are at risk of being considered not medically necessary and denied.

Background and Context

Observation care is a short-term set of services provided to assess, treat, and reassess patients to determine whether inpatient admission is required or if safe discharge is possible. The determination of need for hospitalization relies on clinical factors including history and comorbidities, severity of signs and symptoms, current medical needs, and the risk of adverse events during the period under consideration. Observation services are commonly used after emergency department presentation when a period of monitoring or treatment is necessary to reach an admission or discharge decision.

Key Definitions

inv-13: Observation care — Observation care

DefinitionObservation care: short-term services for assessment, ongoing treatment and reassessment to decide whether inpatient admission or safe discharge is required

Typical durationUsually less than 24 hours

Exceptional casesRarely exceed 2 days (only in rare and exceptional cases)

inv-14: Short inpatient hospital stay — Short inpatient hospital stay: an inpatient stay of less than three midnights (first and second days covered by these criteria).

DefinitionShort inpatient hospital stay: an inpatient stay of less than three midnights

ScopePolicy specifically governs the first and second days of an inpatient stay

Medical necessityAn inpatient level of care for stays <3 midnights is medically necessary only when one of criteria I.A–I.F is met

Admission Criteria

hospital inpatient

Admission indications: Meets one of I.A–I.F (CMS Inpatient Only procedure; ICU/Neonatal Intermediate admission supported by plan's CDS tool; unexpected death; departure against medical advice from a medically necessary inpatient stay; transfer from inpatient stay with total >=3 midnights; election of hospice)

Applies to hospital inpatient admission criteria for short stays (<3 midnights)

Discharge Criteria

For hospital/observation settings, clinical judgment guided by patient history, comorbidities, severity, current needs, and risk of adverse events should determine disposition. Observation is intended as a brief period—usually less than 24 hours and rarely exceeding 2 days—during which the reason for observation may resolve or when assessment indicates no need for inpatient care. When an inpatient admission is required, the inpatient admission and continued-stay rules in this policy apply (including the short-stay criteria for stays under three midnights and the requirement that stays of three midnights or more be supported by nationally-recognized clinical decision support tools).

Day Limits and Observation Duration

inv-18: observation outpatient — Usually less than 24 hours; rarely exceed 2 days

Typical outpatient observation durationUsually less than 24 hours

Maximum expected durationIn only rare and exceptional cases do outpatient observation services span more than 2 days

Clinical determinationDecision for admission vs. discharge based on history, comorbidities, severity, current needs, and risk of adverse events