OASIS-E2 vs. OASIS-E1: What Changed and What It Means for Your Agency

On April 1, 2026, the Centers for Medicare and Medicaid Services (CMS) made the Outcome and Assessment Information Set version E2 (OASIS-E2) the operative standard for all home health assessments. The version that applies to any given assessment is determined by one date: M0090, the date the assessment was completed. Any assessment with an M0090 date on or after April 1, 2026 must use OASIS-E2. Assessments completed before that date use OASIS-E1, even if the episode began earlier (CMS OASIS Data Sets).

OASIS-E1 was in effect for fifteen months, from January 1, 2025 through March 31, 2026. It introduced one new item, removed several that CMS no longer used, and launched the all-payer OASIS mandate. OASIS-E2 arrived as an off-cycle April release with a targeted set of changes: two item replacements, one removal, three items added to the Resumption of Care (ROC) time point, and a new accepted response for one existing item. CMS describes OASIS-E2 as a minor revision, but its extensive change appendix and the volume of updated guidance Q&As suggest the operational implications are more significant than that framing implies.

This article documents every item-level change between OASIS-E1 and OASIS-E2, explains the CMS rationale behind each change, and identifies the specific operational and compliance risks each change creates for agencies in 2026. Agencies that have already transitioned should use this as a verification reference. Agencies that are not yet certain of their OASIS-E2 compliance status should treat this as a gap assessment tool.

For the broader context of how OASIS documentation connects to PDGM (Patient-Driven Groupings Model) payment under the CY 2026 Final Rule, refer to the OASIS-E Documentation Guide and the Complete Guide to Home Health Coding and OASIS Review in 2026.

Key Takeaways

• OASIS-E2 is determined by the M0090 completion date, not the SOC or episode start date. Assessments completed on or after April 1, 2026 require the E2 instrument regardless of when the episode began.
• M0069 (Gender) is replaced by A0810 (Sex). A1250 (Transportation) is replaced by A1255 (Transportation). Neither change alters the underlying clinical data collected; both change item numbers, labels, and in the case of A0810, specific response instructions.
• O0350 (COVID-19 Vaccination) is removed from OASIS-E2 following retirement of the corresponding quality measure from the Home Health Quality Reporting Program (HH QRP). Agencies submitting O0350 on E2 assessments are generating submission errors.
• A1110 (Language), B0200 (Hearing), and B1000 (Vision) are now required at the Resumption of Care time point. These items were previously required only at Start of Care (SOC). This is the highest-risk E2 change because Electronic Health Record (EHR) systems not updated by April 1, 2026 cannot present these items at ROC, and clinicians have no visibility into the missing fields.
• D0150 Column 2 (Symptom Frequency) now accepts a dash response when a patient confirms a symptom but cannot provide frequency information. CMS explicitly states this should be rare. Agencies should monitor dash usage in D0150 Column 2 for overcompliance.
• OASIS-E2 introduced an explicit convention prohibiting agency software from generating OASIS responses on behalf of the clinician. This applies to AI-assisted documentation tools and clinical decision support systems.

What OASIS-E1 Established: The Starting Point for E2

To understand what OASIS-E2 changed, it is necessary to understand what OASIS-E1 left in place. OASIS-E1, effective January 1, 2025, carried forward the structural foundations of OASIS-E. These included the GG0130 and GG0170 functional scoring items that feed PDGM functional impairment level assignment, the Social Determinants of Health (SDOH) items including A1250 and A1300, the BIMS (Brief Interview for Mental Status) cognitive assessment, and the PHQ-2 and PHQ-9 mood assessment items.

OASIS-E1 made three categories of changes from OASIS-E. First, it removed items CMS was no longer using: M0110 (Episode Timing), M2200 (Therapy Need), and the GG discharge goal columns. Second, it added O0350 for COVID-19 vaccination tracking at transfer, death, and discharge time points. Third, it launched the all-payer mandate phase-in, which became mandatory on July 1, 2025 (CMS Home Health Quality Reporting).

OASIS-E2 builds from this E1 baseline. The items it replaces, removes, and adds are all changes relative to what OASIS-E1 established. Agencies that did not fully implement OASIS-E1 carry an additional compliance gap into the E2 period.

Item Replacements: M0069 to A0810 and A1250 to A1255

Two OASIS items were replaced in OASIS-E2. In both cases, the underlying clinical data being collected is the same. What changed is the item number, the item label, and in one case the response-specific instructions.

M0069 (Gender) Replaced by A0810 (Sex)

OASIS-E1 used M0069, item label 'Gender,' to collect the patient's gender identity. The response options were 1 (Male), 2 (Female), and the item included response-specific instructions for patients who do not self-identify a gender.

OASIS-E2 replaces M0069 with A0810, item label 'Patient's Sex.' The response options remain Male and Female. The response-specific instructions from E1 regarding patients who do not self-identify have been removed from E2. This aligns the home health item with the data standard used by the Social Security Administration and the equivalent items in SNF (Skilled Nursing Facility) and IRF (Inpatient Rehabilitation Facility) assessments.

The operational risk is twofold. First, EHR systems that map M0069 in their submission logic rather than A0810 generate item-not-found submission errors for any assessment with M0090 on or after April 1. Second, quality assurance (QA) checklists that reference M0069 require updating to reflect the A0810 item number.

A1250 (Transportation) Replaced by A1255 (Transportation)

OASIS-E1 used A1250 to collect transportation access data as part of the SDOH framework introduced in OASIS-E. The item asked how often lack of reliable transportation prevented the patient from medical appointments or getting things needed for daily living.

OASIS-E2 replaces A1250 with A1255. The question content is unchanged. The response options were consolidated and simplified. M0102 skip-pattern references, which previously pointed to A1250, were updated to reference A1255. Agencies whose EHR skip-logic configurations reference A1250 rather than A1255 may generate edit errors or present incomplete skip patterns to clinicians.

The rationale for this change is cross-setting alignment. A1255 uses the item number and response structure that matches the transportation access item used in other post-acute care settings, enabling CMS to compare SDOH data across settings without item-level translation.

Item Removed: O0350 (COVID-19 Vaccination)

O0350, 'Patient's COVID-19 Vaccination Is Up to Date,' was added in OASIS-E1 at the Transfer, Death at Home, and Discharge time points. It was added specifically to support the COVID-19 vaccine quality measure finalized in the CY 2024 Home Health Final Rule.

OASIS-E2 removes O0350 entirely. CMS retired the corresponding COVID-19 vaccine quality measure from the Home Health Quality Reporting Program, and with the measure gone, O0350 no longer meets the criteria required for an item to remain in the OASIS data set.

The compliance risk here is the reverse of what agencies typically face with new items. Rather than a missing item, agencies must ensure O0350 does not appear in OASIS-E2 assessments. EHR systems that were not updated by April 1, 2026 may still present O0350 as a field at transfer and discharge time points. Clinicians completing those fields are entering data into an item that is not part of the E2 instrument, and the submission may generate edit errors depending on how the Medicare Administrative Contractor (MAC) processes the unexpected item.

Verification Step

• Spot-check a transfer or discharge assessment in the EHR to confirm O0350 no longer appears as a field, this is the fastest way to verify the item is fully removed from the E2 instrument, and it's easy to skip when attention is focused on the higher-visibility ROC additions.

ROC Time Point Additions: A1110, B0200, and B1000

The addition of three items to the Resumption of Care time point is the most operationally significant change in OASIS-E2. In OASIS-E1, A1110 (Language), B0200 (Hearing), and B1000 (Vision) were required only at the Start of Care time point. OASIS-E2 adds all three to the ROC time point as required items.

The Clinical Rationale

The ROC assessment is completed when a patient returns home from an inpatient stay of 24 hours or more for a reason other than diagnostic testing. An inpatient stay, particularly one following a neurological event such as a stroke, can materially affect a patient's hearing, vision, and language function. Collecting these items at ROC rather than relying on the SOC data from earlier in the episode ensures that care planning and care coordination reflect the patient's current sensory and communication status, not a baseline that may have changed during the hospitalization.

This is the same clinical logic that drives collection of functional status and cognitive items at ROC. A patient's condition at ROC may differ substantially from their condition at SOC, and the OASIS is designed to capture that difference at each required time point.

Why This Creates the Highest Operational Risk

The ROC time point additions are the highest-risk change in OASIS-E2 for a specific reason: the failure mode is invisible to clinicians. An EHR system not updated to OASIS-E2 by April 1, 2026 presents clinicians with the OASIS-E1 ROC form. That form does not include A1110, B0200, or B1000. The clinician completes the form presented, submits it, and has no indication the assessment is missing three required items. The missing items do not generate a visible error at completion. They generate a submission error or a compliance finding when the MAC reviews the assessment.

The correction process depends on the MAC jurisdiction and how quickly the agency identified the gap. Agencies that identified the issue immediately after April 1 and implemented a corrective process quickly have a more defensible position than those that continued submitting non-compliant ROC assessments for multiple months. Agencies should consult their compliance advisor to determine the appropriate remediation approach.

EHR Verification Requirement

Every agency should confirm directly with their EHR vendor the date on which the OASIS-E2 ROC instrument update was deployed. If the deployment date was after April 1, 2026, every ROC assessment with M0090 between April 1 and the deployment date was completed on the E1 instrument and is missing A1110, B0200, and B1000. Agencies should document this verification and the corrective actions taken as part of their compliance record.

Red Road Insight: The pattern we consistently see with ROC time point additions is that the compliance gap is identified not by the agency's own QA process but by a MAC review or ADR response. By that point, the gap has often accumulated across dozens of assessments. Early self-identification and documented corrective action consistently produce better outcomes in MAC review than gaps discovered from the outside.

D0150 Column 2: New Accepted Dash Response

D0150 is the Patient Mood Interview, which uses PHQ-2 and PHQ-9 screening to assess depression symptoms. The item has two columns: Column 1 asks whether the patient has experienced each listed symptom, and Column 2 asks how often the symptom occurs.

In OASIS-E1, Column 2 of D0150 did not permit a dash response. If a patient confirmed a symptom in Column 1, the clinician was required to record a frequency in Column 2. OASIS-E2 permits a dash in Column 2 for situations where the patient confirms having a symptom in Column 1 but cannot provide frequency information due to cognitive limitation, communication barrier, or other clinical circumstances.

CMS states explicitly that dash use in D0150 Column 2 is expected to be rare. A dash is not appropriate when the clinician simply cannot obtain a clear response after reasonable effort; there are existing response options for situations where the patient is unable to respond or declines. The dash applies only when the patient confirms the symptom is present but genuinely cannot estimate its frequency.

The QA implication is practical. Before OASIS-E2, a dash in D0150 Column 2 was a submission error. After April 1, 2026, it is a valid response. Agencies whose automated QA tools flag D0150 Column 2 dashes as errors require a rule update. Conversely, if the frequency of D0150 Column 2 dashes increases significantly after the E2 transition, that pattern warrants review to confirm clinicians are applying the dash appropriately rather than using it as a default for difficult interviews.

J1900 Fall Injury Description Updates

J1900 collects information about falls and fall-related injuries since the SOC or ROC date. In OASIS-E2, the item descriptions for J1900B (Injury, except major) and J1900C (Major injury) were updated. The phrase 'Injury (except major)' in J1900B now reads 'Injury (except major): As described in the OASIS manual,' replacing language that had attempted to define injury in the item itself.

This change reflects a CMS decision to move definitional guidance into the OASIS manual rather than embedding it in the item, which allows guidance to be updated without requiring an instrument revision. The practical implication is that clinicians completing J1900 must refer to the OASIS-E2 Guidance Manual for the current definition of injury for J1900B and J1900C, rather than relying on the item description alone.

QA processes that review fall documentation should confirm that clinical staff have access to and are applying the OASIS-E2 Guidance Manual definitions for J1900 injury categories and that training on fall item completion reflects the updated item descriptions rather than the OASIS-E1 language.

New Convention: Software May Not Generate OASIS Responses

OASIS-E2 introduced an explicit convention not present in OASIS-E1: agency software may not generate OASIS responses on behalf of the assessing clinician. Clinical decision support systems and AI-assisted documentation tools may assist with quality review and flag potential inconsistencies. Every OASIS response must be entered by the clinician performing the assessment.

This convention has direct operational implications for agencies that have implemented AI-assisted documentation workflows. If any part of the workflow involves AI or software pre-populating OASIS responses for clinician review and approval rather than clinician entry, that workflow does not meet the OASIS-E2 standard. CMS is signaling that OASIS data quality depends on clinician judgment, not automated inference, and that this expectation is now embedded in the instrument guidance rather than left to policy interpretation.

OASIS-E2 vs. OASIS-E1: Complete Change Reference

Operational Priorities for OASIS-E2 Compliance

For agencies that implemented OASIS-E2 on April 1, 2026, the following priorities remain relevant for ongoing compliance assurance. For agencies that are not yet certain of their E2 compliance status, these are the actions that carry the highest risk if unaddressed.

EHR Configuration Audit

Agencies must verify that their EHR system presents the OASIS-E2 instrument at all applicable time points, with the following specific checks: A0810 replaces M0069 at all time points where gender or sex is collected; A1255 replaces A1250; O0350 does not appear at transfer, death, or discharge time points; A1110, B0200, and B1000 appear at the ROC time point; and D0150 Column 2 permits a dash response. Verification should be documented with written confirmation from the EHR vendor including the date of the E2 deployment.

QA Checklist Revision

Pre-submission QA checklists built for OASIS-E1 must be updated for OASIS-E2. Specifically, the checklist should reflect the new item numbers for sex and transportation, remove O0350 as a review item, add ROC-specific verification for A1110, B0200, and B1000, update J1900 review criteria to reference the E2 Guidance Manual definitions, and add a D0150 Column 2 dash usage review for overcompliance patterns.

ROC Assessment Audit

Agencies should identify their EHR vendor's OASIS-E2 deployment date and audit all ROC assessments with M0090 dates between April 1, 2026 and that deployment date. These assessments were completed on the E1 instrument and are missing the three required ROC items. The number of affected assessments and the corrective actions taken should be documented in the agency's compliance record.

Clinical Staff Re-briefing

Re-briefing on OASIS-E2 should be specific to the changes, not a general OASIS refresher. Clinicians completing ROC assessments require specific instruction on why A1110, B0200, and B1000 are now required at ROC and what clinical circumstances those items are intended to capture. Clinicians completing mood interviews require specific guidance on when the dash response is appropriate for D0150 Column 2 and why overuse of the dash is not compliant. Clinicians using AI-assisted documentation tools require clarity on which functions are permissible under the new AI convention.

How External OASIS Review Supports OASIS-E2 Compliance

Version transitions create structured compliance risk that persists beyond the implementation date. An agency that deployed the OASIS-E2 instrument on April 1 still faces ongoing risk from GG functional scoring drift, D0150 interview consistency, J1900 definition accuracy, and ROC item completion quality across multiple clinicians and branches. These are not one-time transition risks; they are sustained documentation quality challenges that the version change makes more visible.

An external OASIS review function operating as a pre-submission checkpoint provides a layer of review that agency-level QA at high volume cannot consistently maintain. For the specific risks OASIS-E2 introduced, the review focuses on confirming that every ROC assessment includes the three newly required items, that item numbers in submitted assessments reflect the E2 instrument, that D0150 Column 2 dash usage meets the rare-use standard, and that O0350 is not appearing in E2 submissions.

The Bottom Line

OASIS-E2 is a targeted revision. Its item changes are fewer than the OASIS-E transition introduced, but several carry significant operational compliance risk that is not proportional to the number of items changed. The ROC time point additions create an invisible failure mode that produces non-compliant submissions without alerting the clinician. The item replacements and removal require EHR reconfiguration that, if not verified, silently produces submission errors. The AI convention establishes a documentation standard that directly affects agencies using automated tools in their clinical workflows.

Agencies that verified EHR deployment, updated QA checklists, conducted ROC-specific clinical re-briefing, and documented corrective action for the April 1 transition period are well positioned for sustained OASIS-E2 compliance. Agencies that treated the transition as a vendor-managed update without independent verification carry risks that become visible in MAC reviews and ADR responses rather than in internal QA.

How Red Road Supports OASIS-E2 Documentation Accuracy

The pattern we consistently see with ROC time point additions is that the compliance gap is identified not by the agency's own QA process but by a MAC review or ADR response. By that point, the gap has often accumulated across dozens of assessments. Early self-identification and documented corrective action consistently produce better outcomes in MAC review than gaps discovered from the outside.

This mirrors the all-payer mandate baseline. The mandate that became mandatory under OASIS-E1 on July 1, 2025 remains the baseline condition for OASIS-E2 compliance, every E2 change applies to the full eligible census, not just Medicare patients.

Red Road's OASIS review service provides Registered Nurse clinical reviewers who validate every assessment against the current CMS instrument standard before billing. Following the OASIS-E2 effective date, all reviews include: verification that ROC assessments contain A1110, B0200, and B1000; confirmation that A0810 and A1255 appear in place of M0069 and A1250; confirmation that O0350 is not present in E2 submissions; and review of D0150 Column 2 dash responses for clinical appropriateness. Red Road has reviewed more than 2 million charts at a consistent 98% accuracy rate.

Clinician-level and time-point-level error tracking allows agencies to distinguish between EHR configuration gaps and clinical completion gaps, supporting a more targeted corrective response than aggregate accuracy data alone provides.

Explore how Red Road's OASIS review services support documentation accuracy and version compliance.