Medicare Crossover "Lesser-Of" Payment Policy Simulation

Note: This kind of claim-level simulation work spans multiple state Medicaid agencies and payment policy questions: model the change before it goes live, quantify who it affects and by how much, before a state commits to a methodology that can shift substantial payments across its provider network. This project is a representative example.

Problem

A state Medicaid agency was evaluating whether to replace its existing Medicare crossover reimbursement approach with a “lesser of” payment policy: limiting Medicaid payments to the lesser of the Medicaid fee schedule amount or the Medicare beneficiary cost-sharing liability. Before committing to a policy that would reshape payments across the state’s Medicare-Medicaid dual-eligible population, the agency needed a reliable fiscal impact estimate and a clear picture of how different beneficiary populations would be affected, the kind of analysis that has to be right before a policy goes live, not discovered after.

Approach

Built a claim-level payment simulation using a full year of Medicare crossover claims data and the state’s Medicaid fee schedules. Assigned Medicaid reimbursement amounts through a hierarchical pricing methodology using revenue codes, procedure codes, modifiers, and provider-type-specific fee schedules, then sorted claims into confidence tiers based on the strength of each rate assignment match, so agency staff could distinguish highly reliable estimates from lower-confidence ones rather than treating the whole model as equally certain.

Modeled current crossover payments against the simulated lesser-of methodology, then broke the comparison out by beneficiary category: Qualified Medicare Beneficiaries (QMB), Specified Low-Income Medicare Beneficiaries (SLMB), and other Medicare-Medicaid populations, to support policy discussions about exemptions or alternative treatment for specific recipient groups. Claims with unresolved pricing issues or special reimbursement requirements were identified and excluded, keeping the estimate reliable rather than padded with noise.

Outcome

The model estimated that a lesser-of crossover payment policy would reduce Medicaid crossover expenditures by $46.3 million annually across the modeled claims population, with $30.1 million of that impact falling within the highest-confidence pricing tier: a subset of results policymakers could rely on with the least uncertainty.

Breaking the results out by beneficiary category showed that estimated savings varied substantially across QMB, SLMB, and other dual-eligible populations, letting the agency evaluate exemptions or alternative implementation options with the financial tradeoffs already quantified rather than discovered after the policy took effect. The resulting analytical framework is reusable for future crossover policy evaluations and can be refreshed as claims and fee schedule data change.