In Depth Primer for Plan Preview 2025

The high-profile lawsuit losses by the Centers for Medicare and Medicaid Services (CMS) in 2024 and 2025 on Star measures in the Medicare Advantage (MA) program show just how important it is for MA plans to closely scrutinize CMS’s Star calculations and push back when they see issues. CMS offers that chance during the Star Plan Preview periods. Unfortunately, many plans do not invest enough into planning for that process throughout the year. More to the point, many plans are constrained in terms of accessing the right data, having the right analysts, and coordinating throughout the organization.

Plan Preview’s short windows and the challenges outlined put immense strain on even the most sophisticated Stars operations. To help, Lilac Software has created this best practice approach to planning for and engaging with CMS during plan preview to ensure the most accurate and robust Star scores possible.

Background

Plan Preview is divided into two periods – Plan Preview 1 (early to mid-August) and Plan Preview 2 (early to mid-September). We expect Plan Preview 1 for Star Year 2026 to start August 6, 2025. We expect Plan Preview 2 for Star Year 2026 to start September 5, 2025.

In Plan Preview 1 (for 2025 Star, it was August 7 to 14, 2024), CMS provides data and reports that show the values/scores for each measure. Plans should then compare the calculations for each measure to the internal data they have – submitted via HEDIS filings, submitted via Part C and D reporting, external CMS vendor data, or internal analysis of certain measures. Plans have the opportunity in this preview round to alert CMS to discrepancies/errors/anomalies in data and measure calculations. Plans report back to CMS on any errors or discrepancies.

In Plan Preview 2 (for 2025 Star, it was September 6 to 13, 2024), CMS provides data and the actual Star calculations for the coming year, including final values/scores, the cut points, each measure’s Star rating, and the aggregate rollups (Parts C and D summary and overall score along with the Reward Factor or EHO4all and CAI). In this round, plans need to continue to examine measure values/scores, cut points, and the ratings as well as assess the rollups for Parts C, D, and the overall score. This round offers plans a final window to make CMS aware of any remaining data issues as well as issues related to the calculations of measure values/scores and ratings.

 Best Practices On Data Anomalies/Errors/Corrections

CMS is especially strict on Star score corrections when data discrepancies/errors/anomalies are not reported to CMS in a timely fashion. Plans need to practice data oversight strategies continuously throughout the year to demonstrate a track record of reporting data issues as soon as they are known. Early notification of data discrepancies greatly improves the chances that CMS will accept any appeal or challenge. As an example, plans should not expect measure value/score recalculations if an issue is reported for the first time in Plan Preview 2. Plans must report data errors throughout the year and be ready to document data discrepancies/errors/anomalies in Plan Preview 1. Lilac recommends that plans adopt the following due diligence strategies.

• Plans need to establish an ongoing dialogue with CMS and key CMS vendors based on ongoing data review and raising issues while the data is still fresh. It is important that plans are scrutinizing data and the calculations of underlying data throughout the year to quickly identify any inaccuracies. Documentation of conversations and reports is very important. The following areas are examples of where this approach should be applied:

• • Part D PDE processing and medication adherence calculations
  • Disenrollment data
  • IRE timeliness and overturns from IRE published site. Compare to internal data as well.
  • MTM/CMR calculations
  • Call Center Performance
  • Medicare Plan Finder accuracy

• Plan Preview 1 should be focused on data anomalies/errors/corrections, with ties to previous reports of data issues throughout the year if not corrected or still suspect. 
• Overall challenges during both Plan Previews should be focused on questionable accuracy and validity based on arguable data elements. Challenging self-reported data or measure calculation is very difficult during the overall process unless an issue was reported immediately to CMS. 
• If a rigorous process has not occurred, we would encourage the Star unit to ask each department to review various CMS and CMS vendor reports that impact Star scores for any issues prior to June 30.

Leading up to the Plan Preview 1 period 

Here is what you should do in the months leading up to Plan Preview. Remember data discrepancies should be reported to CMS as soon as you are aware of them during the closeout period from January to June for the prior measure year.

• Collect all HEDIS results and ensure correct rounding for Plan Preview.
• Download your final Acumen drug reports (the final June 30 deadline one for the appropriate measure years) for analysis and accuracy. Ensure correct rounding.
• Review the final CMS CAHPS report results for accuracy.
• Review the final CMS HOS report results for accuracy.
• Evaluate your Call Center report for accuracy and file an appeal if you feel calls should not be included or are incorrectly adjudicated.
• Evaluate your disenrollment report and details for accuracy and report discrepancies to CMS.
• Download your final CTMs for analysis.
• Download your final cases from Maximus for the appeals measures (since the June 30 reopens deadline) for analysis and accuracy.
• Review the final MPF report for accuracy.
• Review your Part D filing for MTM CMR.
• Review your Part C filing for SNP-CM.

Lilac’s Support of Plan Preview

In order to facilitate a plan’s review during plan preview, Lilac Software consumes data in order to calculate measure scores as well as the Part C, Part D, and overall ratings. As part of the process, Lilac and client plans enter into a dialogue about any data anomalies/errors/discrepancies that have been raised thus far and documented with CMS. 

For Plan Preview 1

Lilac uses the data submitted by the plan to detail measure attainment against what is reported by CMS. From here, Lilac and the plan undertake any analysis needed to investigate discrepancies and report any errors/discrepancies/anomalies to CMS. In addition, the CAI component is reported in Plan Preview 1. Lilac examines the CMS reported CAI calculation against plan data/previous CAI plan reports/global published CMS reports.

For Plan Preview 2

Lilac uses the Plan Preview 1 data to calculate measure scores as well as aggregate summary and overall scores (including applying all adjustments such as disaster, CAI, Reward Factor, EH04all, etc.). This includes its projections of cut points. 

Lilac uses a range of inputs to forecast cut points, including the following:

• Analysis of over ten years of CMS historical and simulated cut point data. Lilac plots the outliers and four cut points from 1/2 to 4/5) for each measure and overlays plan performance each year.
• Tukey simulations each year.
• Any remaining Tukey “latent” movement that will have to go into SY 2026 and beyond cut points. 
• Assessment of how application of guardrails (to non-CAHPS measures) may impact cut points. 
• Factored in medical trend context (e.g., inflation, utilization, etc.).
• Factored in measure specification changes and electronic ECDS conversion.
• Tenure of measure.
• Analysis for highest historical attainment (average and highest attainment), volatility and changes year over year.
• Analysis of specific COVID impacts by measure (e.g. has the measure recovered, declined, stayed flat since post-COVID utilization began as well as intensity of changes) Data reporting requirements materially diminished
• Literature and contextual review to derive future trends (e.g., as MA enrollment rises, disenrollments have risen and the percentage growth year to year in enrollment impacts disenrollment rates year to year; CAHPS and HOS changes and trends, etc.)
• Factored in industry trends (e.g., areas health plans re making investments in to drive performance).
• Subject matter intuition based on years’ of experience

Post release of Plan Preview 2, Lilac compares all measure scores, ratings, and aggregate CMS ratings against Lilac anticipated. We also compare calculated cut points against the guardrails prescribed in regulation. From here, Lilac undertakes any additional analysis needed to investigate discrepancies and have supporting documentation to submit to CMS.

Map of measures for Plan Preview

Data Needed for Plan Preview

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Interested in learning how Lilac can support your plan during Plan Preview, reach out here to start a conversation with the Lilac team.