The Centers for Medicare & Medicaid Services (CMS) require hospitals subject to the Inpatient Prospective Payment System (IPPS) to complete the Occupational Mix Survey (OMS) every three years. While CMS has not officially released the 2025 survey and instructions, hospitals should begin preparing now.
What Is the Occupational Mix Survey?
The OMS was created to help accurately reflect the actual wage levels in a given area by reporting the differences in hospitals’ staffing mix. Some hospitals might rely heavily on RN’s to provide care to patients, while others choose to employ aides/assistants. Factors such as the available labor market, geographical location, resources, etc., all play a role in the hospital’s decision-making and should not result in payment differences. The OMS calculates average hourly wages for various occupations determined by CMS by using the hospital’s internal payroll dollars and hours. This data is then compiled and used to calculate an Occupational Mix Adjustment Factor (OMAF) for each hospital. The primary goal of the Occupational Mix Adjustment is to eliminate the impact of disparity in skill mix.
Why It Matters for Reimbursement?
The wage index directly impacts the labor-related portion of Medicare reimbursement, which accounts for more than 60% of IPPS payments. Therefore, it is essential to understand the instructions for the OMS and how the OMAF will affect your Medicare reimbursement calculations. It is crucial to understand the following:
- Errors can be costly: misclassifications, inaccurate reporting of contract labor, or missing payroll information may decrease your OMAF, lowering payments for multiple years
- Impact lasts several years: Because CMS collects OMS data once every three years, mistakes in the 2025 survey could affect FFY 2028, FFY 2029, and FFY 2030 wage index calculations
Key Dates and Timeline
CMS has not yet published the official FY 2028 Wage Index Development Timetable, but based on past deadlines, we believe hospitals can prepare for the timeline as follows:
- Reporting Period: January 1 – December 31, 2025
- CMS Issues Survey Form and Instructions: Early 2026
- Hospital Submission Deadline to MACs: Mid-2026 (likely late June or early July)
- Preliminary Public Use Files (PUFs): Released in early 2027, alongside wage index data
- Revision Requests Due to MACs: February 2027
- Final PUFs Published: August 2027
Why Partner With Blue?
The Occupational Mix Survey is complex and can often be challenging to compile all the necessary information for an accurate submission. Blue & Co. believes in a more collaborative approach – by working alongside our clients to streamline data collection and ensure accurate category assignments. If your hospital needs assistance completing the Occupational Mix Survey, our team is here to help.
Kyle Smith, CPA, 340B ACE, Director





