Billing

A/B Rebilling Facts

The following information applies to inpatient hospital admissions on/after 10/1/2013 per final rule CMS-1599-F.

Background

When a Medicare Part A payment cannot be made because an inpatient admission is found to not be reasonable and necessary, Medicare will allow payment under Part B for all hospital services that would have been reasonable and necessary if the beneficiary had been treated as a hospital outpatient, rather than admitted to the hospital as an inpatient. Part B services that specifically require an outpatient status, such as outpatient visits, emergency department visits and observation are excluded from the Part A to B rebilling. The policy also applies when a hospital determines under Medicare’s utilization review requirements that a beneficiary should have received hospital outpatient rather than hospital inpatient services and the beneficiary has already been discharged.

When beneficiaries treated as hospital inpatients are either not entitled to Part A at all, or are entitled to Part A but have exhausted their Part A benefits, hospitals may only bill for the limited set of ancillary Part B inpatient services specified in the Medicare Benefit Policy Manual, Chapter 6, Section 10.2.

Effective Date: Dates of service on or after 10/1/2013

Who is eligible?

All hospitals billing Part A services are eligible to bill the Part B inpatient services including: acute care hospitals, LTCHs, IPFs and IPF units, IRFs and IRF hospital units, CAHs, children’s hospitals, cancer hospitals, Maryland waiver hospitals and other facilities as provided by CMS.

Beneficiary liability

The beneficiary’s patient status remains inpatient as of the time of the inpatient admission through discharge and must not be changed after discharge. Beneficiaries are liable for their usual Part B financial liability. If the beneficiary’s liability under Part A for the initial claim submitted for inpatient services is greater than their liability under Part B, the hospital must refund the beneficiary the difference between the applicable Part A and Part B amounts. If the beneficiary’s liability under Part A is less than their liability under Part B, the beneficiary may face greater cost sharing.

Applicable Services Per Bill Type

Services requiring an outpatient status cannot be billed for the time that the beneficiary was an inpatient, and cannot be included on the Part B inpatient claim. Therefore, only services provided prior to the point of inpatient admission are outpatient services and are not to be included on the 12X Part B claim. Services provided in the 1 or 3 calendar day payment window, prior to the inpatient admission, may be billed on a Part B outpatient claim (13X TOB). Services provided after admission are inpatient services and cannot be included on a 13X outpatient claim. Therefore, two claims may be necessary: one 12X and one 13X claim. Timely filing requirements continue to apply.

Steps:

  • Any pending appeal of the inpatient claim must be canceled in order to proceed with the following steps in the Part A to Part B rebilling process.
  • Determine which services are outpatient (13X claim) versus inpatient (12X claim). Certain services may not be included on either claim; for example, when an inpatient-only procedure was performed prior to the inpatient admission, that inpatient-only service cannot be included on either the 12X or 13X claim.
  • If an inpatient claim has already been billed to Medicare, the hospital must cancel the Part A inpatient claim prior to the submission of a Part B claim for payment. 
  • Medicare requires the hospital to submit a “no pay” Part A (110 TOB) claim indicating the provider is liable for the cost of the Part A service. The claim must include Occurrence Span Code “M1” and the dates of provider liability on the claim. 
  • The hospital may submit an inpatient claim for payment under Part B (12X TOB) for all services that would have been reasonable and necessary if the beneficiary had been treated as a hospital outpatient rather than admitted as a hospital inpatient.
  • Complete a 13X claim for those outpatient services provided prior to the inpatient admission.
  • Ensure all claims are submitted within timely filing requirements.

Part B Inpatient Claim Billing Requirements

  • 837I providers: Place the appropriate Prior Authorization code above into Loop 2300 REF02 (REF01-G1) as follows: REF*G1*A/B Rebilling

DDE or paper claims: add “A/B Rebilling” to FL 63

  • Condition code W2 – attesting that this is a rebilling and no appeal is in process, and
  • The original, denied inpatient claim (CCNDCN/ICN number).

837I providers: place the DCN in the billing notes loop 2300/NTE in the format: NTE*ADD*ABREBILL12345678901234

DDE or paper claims: use the word “ABREBILL” plus the denied inpatient DCN/CCN/ICN to the Remarks Field (FL 80) on the claim using the format: "ABREBILL12345678901234"

*The numeric string 12345678901234 is meant to represent the original claim DCN/ICN numbers from the original denial.

  • TOB = 12X
  • No observation (Revenue code 0762), hospital outpatient visits (Revenue code 045X, 51X) to be billed on the A/B rebilling 12X TOB
  • Providers may not have a pending redetermination request for the Part A denial. The redetermination request will be dismissed if the provider has previously billed a 12X A/B rebilling claim.
  • A/B rebilling claims (12X TOB) will be returned to the provider if there are no medically denied 11X claims in the history that matches the DCN in remarks

Documentation

Hospitals are required to maintain documentation to support all services billing to Medicare including services billed on a Part B inpatient claim for services rendered during the inpatient stay.

Timely filing

Timely filing restrictions apply for Part B inpatient services. Claims that are filed beyond one calendar year from the date of service will be rejected as untimely and will not be paid. Hospitals are required to maintain documentation to support the services billed on the Part B claim(s).

Medicare regulations at 42 CFR 424.44 defines the timely filing period for Medicare fee for service claims. In general, such claims must be filed to the appropriate Medicare claims processing contractor no later than 12 months, or 1 calendar year, after the date the services were furnished.

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