Long-Term Care Hospital (LTCH) Medicare Audit Services: Interrupted Stay Policy Documentation & ADR Response Support

Patients receiving care in a Long-Term Care Hospital frequently require a temporary transfer to another acute care setting — for a surgical procedure, an acute complication requiring intensive care beyond what the LTCH can provide, or another medically necessary reason — before returning to the LTCH to complete their episode of care. Medicare’s interrupted stay policy governs exactly how these temporary absences are counted for payment purposes, and getting the underlying documentation and day-count calculation wrong is one of the more technical, and more consequential, billing errors an LTCH can make. Because the policy involves multiple fixed-day periods that vary by the type of receiving facility, and because it directly affects both length of stay calculations and payment classification, interrupted stay claims are a recurring focus of Medicare Additional Documentation Requests (ADRs).

This article explains how the LTCH interrupted stay policy works, the specific fixed-day periods that apply depending on where the patient was transferred, the documentation elements needed to support correct interrupted stay billing, and how LTCHs should structure an effective ADR response when an interrupted stay claim is challenged. It closes with how HealthBridge US supports LTCHs defending interrupted stay policy documentation.

How the Interrupted Stay Policy Works

Under CMS’s interrupted stay policy, a stay is considered a qualifying interrupted stay when the patient is discharged directly from the LTCH and admitted directly to an inpatient acute care hospital, an inpatient rehabilitation facility, or a skilled nursing facility or swing bed unit, and then returns directly to the same originating LTCH within the applicable fixed-day period for that type of receiving facility. When these conditions are met, the interrupted stay is treated as a single episode of care for LTCH payment purposes rather than as two entirely separate LTCH admissions, which affects both the total length of stay calculation used for site-neutral and short-stay outlier determinations and the underlying LTC-DRG payment itself.

The specific fixed-day period that applies depends on the type of facility the patient was transferred to: a return from an acute care hospital must generally occur within a defined number of days from the date of discharge from the LTCH for the interrupted stay policy to apply, with different, generally shorter fixed-day periods applying to returns from an inpatient rehabilitation facility or a skilled nursing facility or swing bed. LTCHs must track which specific fixed-day period applies to each transfer based on the receiving facility type, since applying the wrong fixed-day period — for example, using the acute care hospital return window for a patient who was actually transferred to a SNF — can result in an incorrect determination of whether the interrupted stay policy applies at all.

The Three-Day Interruption Distinction

A separate, shorter category within this framework applies to interruptions of three days or less. If a patient is discharged from the LTCH and returns within three days without receiving any medical treatment during that interval, the days away from the LTCH are excluded entirely from the total length of stay calculation, as though the interruption never occurred for length-of-stay purposes. However, if the patient receives any treatment during those three days — including treatment the LTCH remains financially responsible for under an arrangement with another provider — those days must be counted in the total length of stay, even though the interruption was brief.

This distinction matters considerably for LTCHs, since a three-day interruption during which the patient received treatment is treated differently than an otherwise identical three-day interruption during which no treatment occurred, purely based on whether treatment was furnished. LTCHs must maintain clear documentation establishing not just the dates of the interruption, but whether treatment was furnished during that specific window, since this single fact determines how the days are counted.

Why Interrupted Stay Claims Draw ADR Scrutiny

Because the interrupted stay policy directly affects the total length of stay figure used in payment classification, and because that calculation depends on facts about the patient’s care at a different facility during the interruption, interrupted stay claims present multiple points where documentation can be incomplete or where the wrong fixed-day period might be applied. Medicare Administrative Contractors (MACs) and other review contractors specifically examine interrupted stay claims to confirm that the discharge and readmission dates are accurately documented, that the correct fixed-day period was applied based on the receiving facility type, and that the treatment-during-interruption determination for any three-day interruption was correctly made and appropriately reflected in the length of stay calculation.

A pattern of interrupted stay claims that consistently favors the LTCH financially — for example, a pattern of readmissions clustering just within the applicable fixed-day window, or interruptions consistently classified as treatment-free when documentation is ambiguous — can also draw broader scrutiny beyond the individual claims themselves, since this is exactly the kind of data pattern that elevates a documentation question into a more significant program integrity concern.

Documentation Elements That Support Correct Interrupted Stay Billing

LTCHs need to maintain clear documentation of the discharge date from the LTCH, the specific type of receiving facility the patient was transferred to, the admission date at that receiving facility, the discharge date from that receiving facility, and the readmission date back to the originating LTCH. This documentation should be sufficient to independently verify which fixed-day period applies and whether the actual interval between discharge and return falls within that window.

For interruptions of three days or less, LTCHs also need documentation specifically addressing whether the patient received treatment during the interruption, including, where the LTCH remained financially responsible for care furnished under an arrangement with another provider, documentation of that arrangement and the treatment furnished under it. Coordination with the receiving facility to obtain contemporaneous records — rather than relying solely on the patient’s or family’s account of what occurred during the interruption — provides a much stronger evidentiary basis for the LTCH’s interrupted stay classification.

Building an ADR Response for Interrupted Stay Claims

When a MAC or other reviewing contractor issues an ADR challenging an interrupted stay claim, the response should assemble the complete timeline documentation: the LTCH discharge date and reason for transfer, the receiving facility’s admission and discharge records, and the LTCH’s own readmission documentation. The accompanying narrative should clearly identify which fixed-day period the LTCH applied and why, based on the receiving facility type, and, for any three-day interruption, should directly address whether treatment was furnished during the interruption and cite the specific documentation supporting that determination.

Where the underlying facts are genuinely ambiguous — for example, where documentation from the receiving facility is incomplete regarding whether any treatment was furnished during a brief interruption — the LTCH should be transparent about the limitation in the response while providing whatever supporting documentation is available, rather than asserting a treatment-free interruption without adequate evidentiary support. Response timelines for interrupted stay ADRs follow the standard Medicare framework of 30 to 45 days depending on the reviewing contractor.

Common Errors in Interrupted Stay Billing

Several recurring errors appear in interrupted stay claims. LTCHs sometimes apply the wrong fixed-day period by failing to distinguish between the different windows applicable to acute care hospital, IRF, and SNF/swing bed returns, particularly when a patient’s transfer involves an intermediate step between facility types. Others fail to obtain adequate documentation from the receiving facility regarding treatment furnished during a brief interruption, leaving the LTCH unable to substantiate a treatment-free classification if questioned. Coordination gaps between the LTCH’s admission staff, who record the return admission, and its billing staff, who apply the interrupted stay day-count logic, can also result in claims that do not accurately reflect the underlying clinical timeline, particularly when the discharge and readmission are handled by different staff members without a shared, reconciled record of the interruption’s specific dates and circumstances.

Building Proactive Interrupted Stay Compliance

LTCHs that experience fewer interrupted stay billing errors generally build a standardized intake process for any patient returning from a temporary transfer, requiring admission staff to document the receiving facility type, the specific dates of the interruption, and whether treatment was furnished, at the time of readmission rather than reconstructing this information later during billing. Coordination agreements with frequently used receiving facilities — the acute care hospitals, IRFs, and SNFs an LTCH most often transfers patients to — that specify what documentation will be provided upon the patient’s return can streamline this process considerably. Regular internal audits of interrupted stay claims, reviewed against the applicable fixed-day periods and treatment-during-interruption documentation standards, help LTCHs identify and correct billing pattern issues before an external MAC review does.

The Interaction Between Interrupted Stays and Site-Neutral Payment

Because the interrupted stay policy affects how a patient’s total length of stay is calculated, it also has downstream implications for the site-neutral payment analysis applied to LTCH discharges, since that analysis depends on the patient’s admission source and clinical history at the immediately preceding IPPS stay. When a patient’s episode of care includes an interrupted stay involving a return to an acute care hospital, LTCHs must carefully evaluate whether that specific acute care encounter — as opposed to the patient’s original, pre-LTCH acute care stay — has any bearing on the site-neutral qualifying criteria for the resumed LTCH stay. This is a nuanced area where the interrupted stay policy’s continuous-episode treatment for length-of-stay purposes does not necessarily simplify the separate, fact-specific site-neutral qualification analysis, and LTCH billing staff should treat the two policies as related but analytically distinct rather than assuming that satisfying one automatically resolves the other. Coordinating with clinical documentation and case management staff who understand both frameworks helps ensure that an interrupted stay does not inadvertently create a site-neutral classification error layered on top of an otherwise correctly documented interruption.

How HealthBridge US Supports Your Long-Term Care Hospital

The interrupted stay policy requires LTCHs to accurately track and document patient movement across multiple care settings and apply the correct fixed-day period based on facility-specific rules, a documentation burden that is easy to underestimate until an ADR arrives. HealthBridge US supports Long-Term Care Hospitals with interrupted stay claim audits, fixed-day period compliance review, coordination process design with frequently used receiving facilities, and ADR response preparation when an interrupted stay claim is challenged. If your LTCH wants to strengthen interrupted stay documentation, clarify how interrupted stays interact with site-neutral classification, or needs support responding to an active ADR, HealthBridge US is here to help — contact our team to discuss your interrupted stay policy compliance and ADR response needs.

References

• Centers for Medicare & Medicaid Services. “Extension of Interrupted Stay Policy Under Long Term Care Hospital PPS” (MM3279). https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNMattersArticles/downloads/MM3279.pdf

• Centers for Medicare & Medicaid Services. “Long-Term Care Hospital PPS: Interrupted Stay Fact Sheet.” https://www.cms.gov/medicare/medicare-fee-for-service-payment/longtermcarehospitalpps/downloads/interrupted_stay_fs.pdf

• Centers for Medicare & Medicaid Services. “Elements of LTCH PPS.” https://www.cms.gov/medicare/payment/prospective-payment-systems/long-term-care-hospital/elements

• Centers for Medicare & Medicaid Services. “Additional Documentation Request.” https://www.cms.gov/data-research/monitoring-programs/medicare-fee-service-compliance-programs/medical-review-education/additional-documentation-request

• Centers for Medicare & Medicaid Services. Medicare Claims Processing Manual, Chapter 29 (Appeals). https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c29.pdf

• Electronic Code of Federal Regulations. 42 CFR Part 412, Subpart O (Long-Term Care Hospital Prospective Payment System). https://www.ecfr.gov/current/title-42/chapter-IV/subchapter-B/part-412/subpart-O

HealthBridge US is here to help. Our audit specialists support Long-Term Care Hospitals with interrupted stay policy documentation and Medicare ADR response — contact us to protect your facility’s reimbursement.