Synthetic demonstration data — State of Cascadia is fictional. Methodology is real.
SEAM FINDER
Provenance Advisors
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Federal disallowance — Medicare primary payer

Dual/COB Mismatch

4,517
Members affected
$101.6M
Estimated exposure
19.1
Avg months at risk
$76.6M–123M
Exposure range

What this is

Members flagged dual-eligible in CBES who are missing from the Medicare COB file, or present with effective dates that don't reconcile — Medicaid paying primary where Medicare should be.

2,711 absent from the COB file · 1,806 present with irreconcilable dates

Why single-system review misses this

Eligibility says dual; claims pays primary; the COB file is a third system on its own monthly cycle. The mismatch lives across all three.

One member, two systems

Member CAS-00000292 — the eligibility record and the payment record, on one clock. The hatched window is the seam.

CBES eligibility spanMMIS enrollment spanthe seam — medicaid paying primary — medicare should be
2023202420252026Medicaid paying primary — Medicare should be — 21.7 mo≈ $1,175/mo at riskvendor cutover 10/25run date 06/26CBESeligibilityMMISpaymentCBES ABD-AGED · Firlands County · 2023-03-08 → 2024-03-02ABD-AGEDCBES ABD-AGED · Firlands County · 2024-09-07 → open · dual-eligibleABD-AGED · DUALMMIS ABD-AGED · Summit Health Plan · CASCADE_LEGACY · 2023-03-08 → 2024-03-02 · capitation YABD-AGED · LEGACYMMIS ABD-AGED · Summit Health Plan · MERIDIAN · 2024-09-07 → open · capitation YABD-AGED · MERIDIAN≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month≈ $1,175 paid this month

The exposure math, in the open

members × avg monthly Medicare-primary cost × avg months unreconciled

4,517members×$1,175avg per month×19.1avg months≈$101.6Mestimated exposure
Example members:CAS-00000292CAS-00000421CAS-00000422CAS-00000706CAS-00000852