Occupational Mix Survey: Payroll Decisions That Can Influence Your Medicare Reimbursement

The Occupational Mix Survey (OMS) remains a critical compliance requirement for hospitals participating in the Medicare Inpatient Prospective Payment System (IPPS). CMS requires this survey every three years to collect detailed payroll data that is used to calculate an Occupational Mix Adjustment Factor (OMAF), which in turn affects a hospital’s average hourly wage and Medicare wage index adjustments. The deadline to submit the 2026 OMS to your Medicare Administrative Contractor (MAC) is June 30, 2026.

Because the OMS directly influences how your hospital’s wages are reflected in the Medicare wage index, payroll classification and reporting decisions can materially affect reimbursement. Below are three key areas providers should prioritize when preparing their OMS submission:

Accurate Job Code Classification
Assigning payroll to the correct occupational categories on the survey ensures that the data used in OMAF calculations truly reflects your labor mix. Misclassification can distort your mix and adversely impact your wage index.

Contract Labor Reporting
The OMS excludes certain wage-related costs such as benefits, unlike standard wage index reporting. That distinction makes precise reporting of contract labor wages and hours especially important — errors or omissions can disproportionately shift your calculated average hourly wage under the occupational mix adjustment.

Calendar Year Pay Period Alignment
Unlike the wage index, which is tied to a hospital’s fiscal year, the OMS requires reporting for calendar year payroll data. Confirming that pay period start/stop dates align with the OMS reporting year is essential to avoid inaccurate totals and unnecessary adjustments.

The occupational mix adjustment exists to help normalize wage index calculations by recognizing differences in regional labor costs and skill-mix, particularly between rural and urban providers. A workforce with a higher proportion of skilled labor should generate higher average hourly wages; accurate OMS reporting ensures this dynamic is captured correctly in CMS’s methodology.

Alliant Support for Members
Completing the Occupational Mix Survey with precision is nuanced and time-intensive. Alliant’s reimbursement specialists can assist member hospitals with review of payroll classifications, contract labor data preparation, and calendar year alignment — helping ensure your OMS submission withstands MAC scrutiny and protects your Medicare reimbursement position.