Insurance Denied Your Hospital Stay? Here's How to Appeal

Few insurance denials are as stressful as being told — sometimes while you are still in the hospital — that your admission is not covered or that your insurer has decided you no longer need inpatient care. These denials can result in thousands of dollars in unexpected costs. Understanding your rights under federal law and clinical review standards is your first line of defense.

Two Types of Hospital Stay Denials

Prospective denials: The insurer denies the hospital admission before or at the time of admission, arguing it does not meet inpatient criteria.

Concurrent (ongoing) denials: The insurer approves initial admission but then, through concurrent review, decides that continued inpatient care is no longer necessary and denies further days.

Both types are appealable — and both require different strategies.

interqual-and-mcg-the-criteria-behind-most-denials">InterQual and MCG: The Criteria Behind Most Denials

Most commercial insurers use one of two commercial clinical decision-support tools to evaluate inpatient admissions:

InterQual: Published by Change Healthcare (now owned by Optum), InterQual criteria specify clinical indicators that support medical necessity for inpatient admission across hundreds of clinical scenarios.

MCG (formerly Milliman Care Guidelines): Published by the Milliman Center for Healthcare Quality, MCG provides evidence-based criteria for admission and length of stay across medical and surgical conditions.

These are not public documents — you must request a copy of the specific criteria applied to your claim. Under most state laws and ERISA, you are entitled to the criteria used in making the decision. Once you have the specific criteria, your physician can write a response documenting exactly how your clinical condition met those criteria.

Observation vs. Inpatient: A Costly Distinction

One of the most confusing and financially damaging hospital billing issues is the observation status problem. Hospitals can admit patients under two different statuses:

• Inpatient admission: Covered under Medicare Part A or your commercial plan's inpatient benefit, typically with fixed deductible and copay
• Observation status (outpatient): Covered under Medicare Part B or your commercial plan's outpatient benefit — which can be more expensive for the patient

Insurers frequently pressure hospitals to place patients under observation rather than inpatient status, even for multi-day stays. For Medicare patients, observation status has historically blocked access to Medicare-covered skilled nursing facility (SNF) care, which requires a 3-consecutive-day inpatient hospital stay.

The NOTICE Act (2016): This federal law requires hospitals to notify Medicare beneficiaries (and, at hospitals' discretion, others) in writing within 36 hours if they are receiving outpatient observation services for more than 24 hours. The notice (called the Medicare Outpatient Observation Notice, or MOON) must explain the financial implications of observation status. If you did not receive a MOON notice and your stay was classified as observation, this is a procedural argument in your appeal.

Your Right to Concurrent Review and Expedited Appeal

Under federal law and most state laws, if your insurer decides to terminate coverage during an active hospital stay, you have the right to:

1. Receive written notice before the coverage termination takes effect
2. Request an expedited appeal — which the insurer must decide within 72 hours (or sooner in urgent cases)
3. Continue receiving care without financial liability while the expedited appeal is pending

This is critical: if your insurer issues a concurrent denial while you are still in the hospital, request an immediate expedited internal appeal. The hospital's case management team can assist with this process.

Building Your Hospital Admission Appeal

For a prospective or retrospective inpatient admission denial:

1. Obtain the InterQual or MCG criteria applied: Request these in writing from the insurer
2. Request the insurer's medical reviewer notes: You are entitled to the rationale used in the denial decision
3. Physician's clinical documentation: Your attending physician should document the specific clinical indicators (vital signs, lab values, imaging findings, clinical trajectory) that justified inpatient admission
4. Peer-to-peer review: Your attending or hospitalist should request a direct call with the insurer's medical reviewer — this is frequently effective for concurrent denials
5. Cite the relevant admission criteria: If your clinical presentation met InterQual or MCG indicators, say so explicitly with specific data points

External Independent Review: Complete Guide" class="auto-link">External Review and Regulatory Complaints

If your internal appeals are exhausted:

• External independent review: Available in all states and required by the ACA for medical necessity determinations on inpatient admissions
• State insurance commissioner: File a complaint for violations of your state's utilization review laws
• CMS: For Medicare Advantage plans, CMS has oversight authority over inappropriate denial patterns

Fight Back With ClaimBack

Hospital stay denials are challenging but frequently overturned when clinical documentation is organized correctly and presented against the specific criteria the insurer applied. ClaimBack helps you build a medical necessity argument matched to your insurer's own review criteria.

Start your hospital stay appeal at ClaimBack

Related Reading

• What Is Medical Necessity?
• Internal vs External Insurance Appeal: Which Should You File?
• How to Write an Insurance Appeal Letter