CY 2026 Midyear Risk Scores: What HCC Coders Should Recheck Before July

Quick Answer

The CY 2026 midyear risk score update, applied on or about July 2026, scores diagnoses from January 1, 2025 through December 31, 2025.

That window is already closed. If a 2025 diagnosis was missed, coded at weak specificity, or captured internally but never reached the submission file, the July run is the last chance to see that gap reflected in payment. This is a 2025 reconciliation exercise, not a 2026 charting sprint.

What Actually Changes At The Midyear Update?

Two things.

First, the payment shift. CMS says initial 2026 risk scores use diagnoses from the prior half-year window, per the CY 2026 Risk Adjustment Implementation Information memo. On or about July 2026, CMS applies the midyear risk scores based on the full January–December 2025 diagnosis year and retroactively adjusts January through June payments when the score changed.

Second, the model context. The 2026 Rate Announcement finalized 100% of non-PACE MA risk scores under the 2024 CMS-HCC model (V28). The old V24/V28 blend is gone. Every specificity gap in a 2025 diagnosis is a V28 problem now, with no partial V24 cushion to soften it.

Community versus long-term institutional status and low-income status can also affect the factor type used after the midyear update, so payment movement isn't driven by diagnosis data alone. Operations teams need to account for that when reading score movement.

Which Dates Of Service Matter For July 2026?

Calendar year 2025. Full stop.

CMS lays out this window in the CY 2026 Risk Adjustment Implementation Information memo: midyear 2026 risk scores use January 2025 through December 2025 diagnoses.

Final 2026 risk scores, applied on or about mid-2027, use that same diagnosis year again with additional monthly status reconciliation.

That matters operationally. Some teams still talk about "2026 coding" as if everything maps to 2026 payment immediately. It doesn't. For the July midyear update, the chart year that counts is 2025.

What Should HCC Coders Recheck Before July 2026?

1. 2025 charts where specificity was thin

CY 2026 uses 100% V28 for non-PACE MA. If a 2025 dx was submitted at an unspecified level, that's a V28 gap now. Unspecified CKD, weak diabetes complication linkage, vague heart failure wording, stale problem-list support for COPD or vascular disease — these are the spots where RAF leakage shows up in the midyear run.

Use the ICD-10 encoder at /encoder to check current V28 mapping on any code path you're unsure about. If a code doesn't map under V28, it didn't move the RAF regardless of what it did under V24.

2. Encounter source and documentation quality

A dx still needs to come from a valid encounter source and be supported in the record that drove the submission. If the team is still cleaning up chart review workflows, the midyear run isn't the place to assume a diagnosis is safe because it reached the file. Source integrity is a 2027 Rate Announcement issue too — CMS finalized exclusions for unlinked chart reviews and audio-only diagnoses starting CY 2027, which signals the direction reviewers are heading.

3. Late 2025 diagnoses that may not have reached the submission pipeline

The July refresh picks up the full January through December 2025 year. A chart corrected internally in Q4 2025 that never made it into the submitted data stream won't help the midyear score. Check whether late-year coder corrections and accepted addenda were properly incorporated before the submission deadline.

See the encounter data submission deadlines guide if you're unsure where the cutoff landed for 2025 data.

4. Training materials that still teach blend-year logic

The three-year phase-in of V28 is complete. If your internal cheat sheets still show 2024 or 2025 blend percentages, they're wrong for current-year payment. Any reference to "67/33" or "33/67" blending belongs to history now.

See the V28 transition hub at /hcc-v28 for a current-model reference.

Do The 2026 Midyear And Final Mapping Files Change The Coding Rules?

No. The files change what the systems run, not the underlying coding standard.

CMS publishes separate 2026 Midyear/Final ICD-10 Mappings and 2026 Midyear/Final Model Software on the official risk adjustment page. Those files are the production-grade references behind the payment run. For plans, vendors, and analysts, they're the right place to confirm what mapping logic CMS is actually using.

For coders, the practical meaning is narrower. The files don't make an unsupported dx reportable. They don't make a weak note stronger. They tell you which mappings and model logic the 2026 payment run is using, so they're the reference to reach for when a mapping assumption is in dispute.

Why Should MA Teams Care About The Python Model Software Release?

Because CMS is showing where the tooling is going.

The CY 2026 Implementation Memo says CMS is transitioning risk adjustment software away from SAS and that CY 2026 Mid-Year/Final software is available in both SAS and Python. CMS also says it intends to release Python-only software starting with CY 2028 Initial.

That's not a day-to-day coding workflow change. But for plan operations, analytics teams, and vendors that reconcile risk scores against CMS model logic, this transition is no longer theoretical. If your team does internal model validation or external score checking, the Python release is now part of the real operational picture.

What Should Coding Managers And MA Operations Leads Do This Week?

Keep it concrete.

Pull a 2025 diagnosis reconciliation list. Focus on the HCC families where V28 specificity made the biggest difference: CKD with staging, diabetes with complication linkage, heart failure type and acuity, COPD, vascular specificity, and major depressive disorder severity. These are where nonspecific 2025 coding costs the most in the July run.

Use the RAF calculator at /raf to model the payment difference between specific and nonspecific code paths for any of these families before you prioritize the recheck.

Separate chart support issues from submission pipeline issues. Some missed score movement is a documentation or coding problem. Some is a data-delivery problem. Treating them as the same failure mode makes both harder to fix.

Confirm your reference tools reflect the 2026 production model. The CMS 2026 model software and mapping page is the source of truth. If an internal spreadsheet, vendor export, or training guide disagrees with that source, the source wins.

Where HCC Buddy Fits

HCC Buddy is useful for the 2025 diagnosis-side of this recheck. Confirm the ICD-10-CM code path, compare V28 HCC mapping, and check whether the specificity level in the documentation is enough to get the code where you need it.

It doesn't replace the submission audit, the encounter-source review, or the plan-side reconciliation step. Midyear score movement is where coding accuracy and operational follow-through meet the payment file. Both have to be clean.

Start with the condition families where V28 specificity cost the most — CKD staging, diabetes complication linkage, heart failure type — and run each questionable 2025 code path through the ICD-10 encoder at /encoder before July.

Sources

CMS CY 2026 Risk Adjustment Implementation Information memo (dated September 29, 2025)

CMS 2026 Model Software and ICD-10 Mappings page

CMS 2026 Medicare Advantage and Part D Rate Announcement fact sheet, April 7, 2025