Medicare Part A
The hospital insurance part of Medicare, covering inpatient hospital, skilled nursing facility, hospice, and limited home health.
1 min read · Last reviewed May 23, 2026
At a glance
- Category
- Payer
- Primary sources
- 1
- Workspace handoff
- ask d3 →
Where this comes up
Front-office and billing both hit this term — eligibility before the visit, prior auth before the procedure, contract terms during fee-schedule negotiation, and credentialing whenever a new provider joins or a payer roster lapses. Misses here become denials downstream.
Full definition
What it is in practice
CMS covers Part A automatically for most beneficiaries age 65+ with sufficient work history. Beneficiaries pay a deductible per benefit period and coinsurance for extended stays.
How it shows up in your practice
Hospitals bill Part A on the UB-04 / 837I. Physician services delivered during an inpatient stay bill professional under Part B with POS 21.
Sources
- CMS — Acute Inpatient PPShttps://www.cms.gov/medicare/payment/prospective-payment-systems/acute-inpatient-pps
Look up Medicare Part A rules in Ask D3
Open ask d3 →Related terms
- PayerMedicare Part BThe medical insurance part of Medicare, covering physician services, outpatient care, durable medical equipment, and preventive services.
- PayerMedicare Part DMedicare prescription drug coverage delivered through stand-alone PDPs or MA-PD plans.
- BillingMS-DRGMedicare Severity Diagnosis Related Groups — the classification system used to pay inpatient hospital admissions under Medicare's prospective payment system.
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Related across the archive
- GlossaryMS-DRGMedicare Severity Diagnosis Related Groups — the classification system used to pay inpatient hospital admissions under Medicare's prospective payment system.
- GlossaryMedicare Part BThe medical insurance part of Medicare, covering physician services, outpatient care, durable medical equipment, and preventive services.
- GlossaryMedicare Part DMedicare prescription drug coverage delivered through stand-alone PDPs or MA-PD plans.
- GlossaryInpatient Hospital BillingFacility billing for hospitalized patients, classified using the MS-DRG system under the Acute Inpatient Prospective Payment System.
- ComplianceOIG LEIE Monthly Exclusion Screening: Process + Audit-Ready LogsMonthly OIG LEIE and SAM.gov exclusion screening for every workforce member and vendor: the workflow, the log fields auditors require, and the escalation path.
- CompliancePECOS Provider Enrollment Verification (2026) — Quarterly ChecklistQuarterly PECOS provider enrollment verification workflow: who to check, the exact lookup steps, the audit log columns, and the revalidation escalation path.
- GlossaryMedicare Part C (Medicare Advantage)Medicare benefits delivered through private health plans contracted with CMS, often with additional benefits and a managed-care structure.
- RegulationMLN: 'Incident To' Services in Medicare Part BReference to Medicare's incident-to billing rules permitting auxiliary personnel to furnish services billed under the physician's NPI, with strict supervision and treatment-plan requirements.
This glossary entry is a research aid for billing and compliance staff. It does not provide legal, medical, or financial advice and does not replace counsel. References cited link to primary sources at HHS, OCR, CMS, eCFR, NIST, and the relevant payer or industry body.