Navigating the Shift to Market-Based MS-DRG Reporting
CMS is moving Medicare inpatient reimbursement toward a more market-driven model and hospitals need to prepare now. As part of the finalized 2026 OPPS rule, CMS introduced new cost report worksheets that leverage pricing transparency data to support future changes to MS-DRG relative weights.
While full implementation of market-based MS-DRG weighting does not begin until Federal Fiscal Year 2029, hospitals with cost report year-ends after January 1, 2026 are required to begin reporting the underlying data. This is not a theoretical exercise. The way hospitals prepare and report now will directly influence future reimbursement benchmarks.
What’s Changing
CMS plans to transition MS-DRG relative weights away from a purely cost-based methodology toward a market-driven approach that reflects negotiated Medicare Advantage payment rates. To support this shift, CMS has finalized new inpatient reporting requirements within the cost report.
The intent is clear: Medicare Advantage contracted rates will increasingly inform how CMS evaluates inpatient resource use and payment adequacy across MS-DRGs.
New Reporting Requirement
CMS is expected to introduce a new cost report worksheet (anticipated as Worksheet S-12) requiring hospitals to report the median negotiated payment rate by MS-DRG across all Medicare Advantage payers.
Key parameters include:
- “Negotiated charges” should be interpreted as negotiated payment rates, not billed charges
- Only paid inpatient Medicare Advantage discharges are included
- Denied, zero-paid, and unpaid accounts are excluded
- Reporting applies at the MS-DRG level, aggregated across Medicare Advantage payers
This requirement introduces a new level of complexity, pulling together pricing transparency files, payer contracts, and discharge-level data into a single reporting framework.
How Hospitals Should Prepare
Hospitals that treat this as a late-stage reporting exercise risk unnecessary disruption. Preparation should begin well in advance of cost report submission.
Recommended steps include:
- Validate pricing transparency data
Review your most recent machine-readable file (MRF) and confirm that all Medicare Advantage inpatient rates—or pricing algorithms—are complete, accurate, and usable. - Identify applicable discharges
Generate a discharge listing for the cost report year that includes only inpatient stays paid under negotiated Medicare Advantage rates. - Align rates to MS-DRGs
For each MS-DRG, pair the negotiated payment rate from the MRF with corresponding Medicare Advantage discharges. - Calculate median rates
Determine the median negotiated payment rate for each MS-DRG and prepare that data for cost report entry. - Monitor CMS guidance closely
CMS has indicated that additional cost report instructions will be released. Hospitals should expect clarification on methodology, edge cases, and audit considerations.
Why This Matters
This reporting requirement is not isolated. It represents an early step in reshaping how CMS evaluates inpatient payment fairness and efficiency. Hospitals that understand their Medicare Advantage rate structure and how it compares across MS-DRGs will be better positioned to:
- Anticipate reimbursement pressure
- Identify contracting vulnerabilities
- Support future negotiations with data-backed insights
- Reduce risk tied to incomplete or inconsistent reporting
How Alliant Supports Members
Alliant Purchasing helps members navigate complex regulatory changes by connecting financial, operational, and market intelligence into practical action. Through partnerships and advisory resources, Alliant supports hospitals as they align pricing transparency, managed care strategy, and compliance requirements—without adding unnecessary burden to internal teams.
For growth-focused organizations, preparation is not about checking a box. It’s about protecting margin, reducing risk, and staying ahead of where reimbursement policy is headed next.
