The Medicare Occupational Mix Survey (OMS) is a key reporting requirement for hospitals that operate on a prospective payment system (PPS), directly influencing wage index calculations and Medicare reimbursement. Because the occupational mix survey influences wage index calculations for three years, even modest reporting errors can have lasting financial impacts until the next review cycle.
With the June 30, 2026 submission deadline approaching, hospitals must make sure their CY 2025 wage and hour data are complete, accurately classified, and defensible with appropriate documentation. Hospitals need to start earlier than they think to make sure they have enough time to compile and validate their data.
Important Deadlines
| June 30th, 2026 | July 13th, 2026 (Anticipated) | September 1st, 2026 |
Deadline for survey submission | CMS public use file (PUF) posting | Deadline to submit revision requests with supporting documentation |
Understanding the Occupational Mix Survey
The OMS carries such a high level of financial impact because of how The Centers for Medicare and Medicaid Services (CMS) uses the data. As authorized under Section 1886(d)(3)(E) of the Social Security Act, CMS requires short-term, acute-care PPS hospitals to submit occupational mix data every three years. CMS uses this data to calculate each hospital’s Occupational Mix Adjustment Factor (OMAF), which modifies the labor-related portion of the Medicare wage index. Because the wage index directly influences inpatient prospective payment system (IPPS) reimbursements, the occupational mix submission can materially affect hospital financial performance for FY 2028–2030 by altering revenue and compressing margins.
While the survey may appear straightforward — a simple data pull of nurses’ wages — the process involves multiple departments, complex classification rules, and a tight window for correction. As a result, PPS hospitals often encounter unexpected operational and technical challenges.
Audit issues are common and even small errors can compound to have an outsized effect on reimbursement. In a working example from CMS guidance, a hospital with a registered nurse (RN) mix higher than the national average received an OAMF of 0.9757 — a reduction that, applied across a mid-sized hospital's Medicare volume, can translate into millions of dollars in reimbursement impact compounded over three fiscal years.
Key Challenges of the OMS:
| Data Extraction and Mapping | Aligning payroll and HR systems with CMS occupational categories requires detailed reconciliation. Payroll codes rarely map cleanly to CMS definitions, and gaps can skew the final submission in ways that aren't immediately visible. |
| Classification Complexity | Nursing staff, contract labor, and hybrid roles present ongoing classification challenges. Misclassifying even a subset of these employees can materially affect the wage index calculation. |
| Impact Projection | Many hospitals do not have the tools or institutional knowledge to model how their occupational mix data will affect their wage index before they submit. Without that visibility, it can be difficult to identify problems and opportunities in advance. |
| Cross-Department Coordination | Finance, HR, payroll, and reimbursement teams must work together to verify that occupational mix data is consistent with cost report wage information. |
| Documentation Readiness | Revision requests require complete, detailed supporting documentation. Hospitals that do not organize their records in advance often find that the revision deadline arrives before they are ready to respond. |
| Timing Pressure | Internal validation, benchmarking, and review take more time than most teams anticipate. Hospitals that begin the process close to the submission deadline routinely find themselves making rushed decisions that carry long-term financial consequences. |
Failure to submit by June 30 or to provide complete and accurate information can have long-term financial impacts that may extend across multiple fiscal years. Specific impacts could include:
- Loss of opportunity to influence the FY 2028–2030 wage index
- Reduced Medicare reimbursement if occupational classifications understate wage intensity
- Increased audit scrutiny from CMS
Your Occupational Mix Survey Checklist
- Confirm Data Completeness: Make sure at least 11 months of CY 2025 wage and hour data are available and properly reconciled.
- Validate Occupational Classifications: Review role mapping against CMS definitions, particularly for nursing, contract labor, and specialty positions.
- Reconcile to Cost Report and Payroll Systems: Confirm consistency between occupational mix data, payroll records, and cost report wage information.
- Conduct Internal Review and Benchmarking: Assess results for reasonableness and identify anomalies before submission.
- Prepare Documentation in Advance: Organize supporting records to enable rapid response if revisions are necessary after CMS posts the PUF.
- Monitor CMS PUF: Promptly review preliminary published data and identify discrepancies prior to the September 1 revision deadline.
Looking Beyond Compliance
The Occupational Mix Survey should not be viewed as a standalone reporting obligation. Because the wage index is a composite calculation, the occupational mix adjustment interacts with other elements of the formula in ways that can amplify or offset its impact. An OMS submission that appears favorable in isolation may produce unexpected reimbursement movement once incorporated into the full wage index calculation.
Anticipating that movement requires modeling the occupational mix impact within the broader wage index framework. This analysis allows hospitals to fully understand how FY 2028–2030 payments may shift before CMS data becomes final, and better align staffing, wage data, and reimbursement strategy with long-term financial sustainability.
But many hospitals lack the time, tools, or analytical resources to evaluate and model reimbursement adjustments. These hospitals may benefit from an experienced third party that can validate occupational mapping, test results within the full wage index calculation, and assess documentation readiness.
Once hospitals begin analyzing the wage index more holistically, the insights they gain often extend beyond the occupational mix survey itself. A deeper review of wage index positioning can help providers evaluate broader reimbursement strategies. For example, analyzing current wage index trends — not just historical data from the survey period — can help hospitals determine whether they may qualify for geographic reclassification, which can significantly affect reimbursement.
Providers that move beyond a narrow compliance lens can use the full universe of wage and staffing data to inform broader financial planning and market positioning in the years ahead.
How BDO Can Help
When survey results influence three fiscal years of payment, accuracy and completeness are key. Working with a third-party advisor can give you confidence in your data and future financial stability.
BDO has deep experience across the full wage index and IPPS reimbursement landscape. Our teams include knowledgeable reimbursement professionals who routinely work with Medicare cost reports, geographic reclassification strategy, wage index development, and CMS review processes. Our integrated and holistic perspective enables hospitals to evaluate occupational mix data within the broader context of reimbursement positioning, identify potential misalignment, model the downstream impact of submission data, and anticipate documentation needs before deadlines compress options. With the recent expansion of our healthcare reimbursement team, we continue to broaden the perspectives and capabilities we bring to this work. Additional background on this expansion is available at https://www.bdo.com/horne.
Need support for your CY 2025 Medicare Occupational Mix Survey Submission? Contact us.