OASIS sequencing sounds straightforward: complete the right assessment at the right time. In practice, however, it can become complicated very quickly when:
- a patient is hospitalized,
- refuses a discharge visit,
- experiences a significant change in condition,
- or returns from the hospital near the end of a certification period.
That’s why The Home Health Consultant Co-Founder Mariam Treystman recently dedicated a webinar to OASIS Time Points and Sequencing for Medicare-certified home health agencies.
*This article was written in consultation with Mariam Treystman.
OASIS sequencing has become one of the most common compliance issues our team has encountered during home health surveys. As Mariam explained,
“Besides survey status, issues in this area can also affect your outcome scores and your reimbursement.”
Understanding the time points is therefore about much more than completing another form. Agencies need processes that help clinicians recognize which OASIS is required, what date controls the assessment, and what to do when the patient's situation does not follow the expected sequence.
Which Home Health Patients Require OASIS?
As of July 1, 2025, OASIS applies broadly to home health patients regardless of payer.
That means agencies should not assume OASIS applies only because Medicare is paying for the care. Private insurance patients and even patients receiving services without payment may still require OASIS.
The primary exceptions discussed in the webinar include:
- Pediatric patients
- Maternity-only patients
- Patients receiving only personal care or homemaker services without a qualifying skilled service
There are also limited circumstances involving therapy services billed outside of the Medicare home health benefit where OASIS may not apply.
Who Can Complete an OASIS Assessment?
OASIS must be completed by an appropriately qualified evaluating clinician.
- Home health aides,
- LVNs/LPNs,
- physical therapist assistants,
- and similar assistant-level staff
…cannot independently complete an OASIS assessment.
When nursing is ordered and involved in the case, the RN generally completes the OASIS and determines Medicare eligibility. When the patient has a therapy-only case without nursing, an eligible therapist may establish the start of care and complete the OASIS.
This distinction becomes especially important when agencies routinely send an RN to “open” therapy-only cases.
If nursing is not medically necessary and is not actually being provided as an ordered service, an RN visit performed solely to complete OASIS is not automatically a billable nursing visit.
Mariam cautioned agencies to pay close attention to this because an improperly billed visit may become a problem during an Additional Documentation Request (ADR).
The Main OASIS Time Points Home Health Agencies Need to Know
Although unusual situations create many of the sequencing questions, agencies should begin with the basic assessment timeframes.
Start of Care
A Start of Care OASIS is required when the patient begins qualifying home health services.
The comprehensive assessment must be completed within five calendar days after the Start of Care date, with the SOC date considered day zero.
Recertification
For a patient continuing into another 60-day certification period, the follow-up assessment used for recertification must generally occur during the last five days of the current 60-day period—days 56 through 60.
Transfer to an Inpatient Facility
A qualifying inpatient transfer generally requires a transfer OASIS when the patient is admitted to an inpatient facility for 24 hours or longer for reasons other than diagnostic testing.
The transfer assessment must generally be completed within two calendar days of the transfer date or the agency learning of the qualifying transfer.
That “knowledge of” language matters.
An agency may not always learn immediately that a patient went to the hospital. If the agency genuinely did not know about the hospitalization until a later visit, the assessment timeframe begins when the agency becomes aware of the event.
Resumption of Care
When the patient returns home following a qualifying inpatient stay and remains under the agency's care, a Resumption of Care OASIS may be required.
The ROC assessment generally must be completed within two calendar days of the inpatient facility discharge or the agency learning that the patient returned home.
Significant Change in Condition
A patient may experience a substantial change during the certification period without being hospitalized.
When the patient's condition changes enough to meet the agency's criteria for a significant change assessment, the agency may complete an Other Follow-Up OASIS.
This allows the agency to reassess the patient's current status rather than waiting until the next scheduled OASIS time point.
What Happens When a Patient Cannot Receive a Discharge Visit?
Unplanned or non-visit discharges are among the most confusing OASIS situations for agencies.
Examples include a patient who:
- Suddenly refuses further home health services
- Moves outside the service area
- Cannot be reached
- Becomes unavailable before a planned discharge assessment can occur
CMS guidance allows a qualified clinician, who previously saw the patient in person, to complete the discharge comprehensive assessment using information from that clinician's own prior visit.
The clinician may also supplement that assessment with information documented during other agency visits occurring within the applicable recent five-day period.
This is important because the process should not simply be treated as copying the patient's previous OASIS.
As Mariam explained, current guidance expects the agency to use the available clinical information appropriately, while still grounding the assessment in a qualified clinician's prior face-to-face encounter.
The person completing the discharge OASIS therefore must be a qualified clinician who actually saw the patient.
A supervisor who never evaluated the patient cannot simply review the chart, call the patient, and complete the OASIS using someone else's documentation.
If the most recent qualified clinician is unavailable, the agency should first determine whether another discharge visit can be performed. If not, another qualified clinician who previously saw the patient may potentially complete the assessment based upon that clinician's own prior encounter.
Documentation becomes particularly important in these cases. The record should clearly distinguish:
- The clinician's last in-person visit
- The patient's actual discharge or refusal date
- The assessment completion date
- The effective discharge date
These dates may not be the same.
What If You Find Out About a Hospitalization Weeks Later?
Consider a patient receiving infrequent visits:
The clinician arrives on March 20 and discovers that the patient was hospitalized on March 2, subsequently discharged, and has already returned home.
First, determine whether the hospitalization actually met the criteria for a qualifying inpatient transfer.
If it did not, the agency may document the hospitalization and notify the physician without necessarily creating transfer and ROC OASIS assessments.
If it did qualify, however, the agency must address the missed sequencing even though several weeks have passed.
The transfer date would still reflect the actual March 2 transfer. But because the agency did not learn about the hospitalization until March 20, the agency would generally have two calendar days from becoming aware of the event to complete the necessary assessment.
A corresponding ROC assessment may also be required.
The key principle is simple:
A late discovery is different from a late response.
If the agency genuinely did not know about the hospitalization, it should act promptly once it learns what happened.
What If the First Person Back in the Home Cannot Complete OASIS?
Another unusual situation occurs when an LVN, home health aide, or therapist assistant visits the patient and discovers that the patient was hospitalized and has already returned home.
That staff member may have been the first person providing care after the patient's return, but cannot complete the required OASIS.
The agency must send a qualified clinician to complete the transfer and ROC requirements.
However, the ROC date is tied to the first home health service visit after the inpatient stay, even if that visit was performed by someone who could not complete the OASIS.
This is an important distinction between the date of the event and the date the OASIS is actually completed.
Hospitalizations Near Recertification Require Extra Attention
Sequencing becomes especially complicated when hospitalization occurs around days 56 through 60.
For example, what happens if the recertification assessment has already been completed and the patient is hospitalized before the certification period ends?
Depending on whether the agency discharges the patient and when the patient returns home, the next assessment may be a Transfer, ROC, or new SOC.
One of the most useful rules from the webinar is this:
If the patient returns before the certification period ends, the agency may generally resume care with an ROC. If the inpatient stay extends beyond the certification period and the patient returns afterward, a new SOC may be required.
There is another important variation.
If a patient is hospitalized on day 58 before the recertification assessment has been completed, the agency completes the appropriate transfer assessment. If the patient returns while the ROC and recertification assessment windows overlap, the ROC may satisfy both requirements.
If the hospitalization extends beyond the end of the certification period, the patient may instead require a new Start of Care when returning home.
Significant Change OASIS Does Not Rewrite the Previous 30-Day Payment Period
Under PDGM, agencies may also wonder whether completing an Other Follow-Up assessment after a significant change allows them to revise the patient's original payment grouping.
According to the guidance discussed in the webinar, the answer is generally no.
The case-mix group cannot simply be changed retroactively within an already established 30-day payment period.
A qualifying follow-up assessment may affect the next 30-day payment period, but it does not automatically rewrite the first 30 days.
Agencies should work closely with their billing team when a follow-up assessment changes information that affects payment grouping.
OASIS Sequencing Should Be Part of Your Compliance Monitoring
Many OASIS problems do not begin because clinicians do not understand how to complete the assessment itself.
They happen because no one recognizes that another OASIS time point has been triggered.
Agencies should have processes for identifying:
- hospitalizations,
- patient returns,
- significant changes,
- upcoming recertifications,
- Refusals,
- and unexpected discharges
…as soon as possible.
Clinical and administrative teams should also understand that the:
- visit date,
- assessment completion date,
- transfer date,
- discharge date,
- and ROC date are not automatically interchangeable
As Mariam emphasized throughout the webinar, unusual situations should not simply be forced into the agency's normal workflow.
When something does not fit the expected sequence, stop and determine:
What event occurred? When did it occur? When did the agency learn about it? Which assessment does that event trigger? And what date actually controls the OASIS requirement?
Getting those questions right can protect the agency's survey compliance, clinical reporting, and reimbursement, and prevent a seemingly small sequencing error from becoming a much larger problem.
OASIS sequencing is only one part of maintaining year-round home health compliance. The Home Health Consultant’s Administrative Compliance Program helps agencies stay on top of OASIS, QAPI, clinical documentation, survey preparation and other ongoing compliance requirements. Learn more about the importance of compliance maintenance in the article below:
*Disclaimer: The content provided in this article is not intended to be, nor should it be construed as, legal, financial, or professional advice. No consultant-client relationship is established by engaging with this content. You should seek the advice of a qualified attorney, financial advisor, or other professional regarding any legal or business matters. The consultant assumes no liability for any actions taken based on the information provided.
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