July 21 2025
OASIS Answers
Categories: OASIS

Understanding M0090: Date Assessment Completed in OASIS-E1

by Kerry Termine, DPT, HCS-D, COS-C

In our Blueprint for OASIS Accuracy 2-day OASIS-E1 training, the topic of when the OASIS assessments are complete has been eye-opening for many attendees. Per the OASIS guidance found in the OASIS-E1 Guidance Manual and CMS OASIS Q&As, M0090 – Date Assessment Completed – is the last date that information used to complete the comprehensive assessment and determine OASIS coding was gathered by the assessing clinician and documentation of the specific information/responses was completed. M0090 is collected at every OASIS time point.

For example, in a situation where the clinician needs to follow up off-site with the patient’s family or physician to complete a specific OASIS item the patient is unable to answer, M0090 should reflect that follow-up date—even if no visit occurred on that day. However, if an error is identified at any time, it should be corrected following the agency’s correction policy, and M0090 would not necessarily be changed.

What Is the Comprehensive Assessment?

OASIS guidance defines the comprehensive assessment as a legal document, and when signed by the assessing clinician, the signature serves as an attestation that the document—including OASIS responses—reflects the patient’s status as assessed, documented, and/or supported in the clinical record.

OASIS data are collected as part of the comprehensive assessment required by the Medicare Home Health Conditions of Participation. It’s important to note: OASIS is not intended to represent the entire comprehensive assessment on its own. HHAs must integrate OASIS items into their broader assessment process and follow their own policies and procedures.

How Agencies Should Handle Collaborative Assessments

Agencies may have the comprehensive assessments (including OASIS, if applicable) completed by a single clinician. However, if collaboration with other healthcare personnel or staff occurs, the agency is responsible for developing clear policies and documentation standards for how this information is gathered, shared, and recorded in the patient’s clinical record. These policies must align with CMS requirements and accepted clinical practice standards.

Why M0090 Can Be Confusing for Clinicians

Many agencies include internal reviews of OASIS assessments to improve accuracy and completeness. While these reviews are helpful, they can cause confusion—especially when it comes to how they affect M0090.

According to CMS OASIS Q&As (Category 2, Q37.6), when a potential inconsistency is found within the assessment timeframe (even by a third-party reviewer), the assessing clinician may consider that feedback and revise OASIS responses—as long as it’s within the allowed timeframe and aligns with OASIS guidance.

How Review Feedback Can Impact the M0090 Date

If the clinician uses that review feedback to update the comprehensive assessment and determine final OASIS coding, then M0090 should reflect the last date that information was gathered and documented—even if that includes internal discussions with a reviewer to resolve discrepancies.

Correcting Errors Without Changing M0090

Per CMS OASIS Q&As (Category 2, Q37.3), if a true error (not just a discrepancy) is found after review—such as through a supervisor or audit—it should be corrected using the agency’s established correction policy and documentation standards.

However, unless the updated information involved new data collection, M0090 does not need to be changed just because an error was found and corrected.

Questions related to OASIS coding and documentation of the OASIS responses can be sent to the Home Health Quality Help Desk: homehealthqualityquestions@cms.hhs.gov.

This is only a small sample of topics covered and key insights gained by attending the OASIS Answers, Inc. Blueprint for OASIS Accuracy 2-day training. We hope to see you there in the near future!