Idaho Medicaid ex parte renewal share, August 2026

Ex parte share measures how much of the renewal burden the state carries instead of the beneficiary. It trends with data-matching infrastructure, which improves in vendor-release steps rather than smoothly.

Latest 99.6 (02/26); mean monthly change over trailing window 4.16pp; damped six-month projection = 98.0.

Half-weight trend continuation with volatility-scaled uncertainty; renewal cohorts differ month to month, so the interval is wider than the point trend alone would suggest.

The resolver is an Idaho state row, not a national weighted average: the original first-publication August 2026 reporting-period row in CMS State Medicaid and CHIP Eligibility Processing Data. The target is the share of completed Medicaid renewals processed ex parte, in percent rounded to one decimal.

Base-rate/reference class: the relevant outside view is Idaho's own recent original-submission first-print run, because this resolves a single state row. The five inspected values average 81.8 percent, span 70.9 to 99.6 percent, and have a latest value of 99.6 percent; intervening months were unavailable in the inspected context rather than intentionally excluded.

Level, momentum, and mechanism: the latest February 2026 value is almost at the ceiling, which could reflect a real data-match or system improvement, but Idaho's recent history also includes a drop from 83.2 percent to 70.9 percent before the jump to 99.6 percent. I therefore treat the latest value as highly informative but not fully persistent.

Prior/update/interval: prior model is latest-value persistence blended with a five-point Idaho mean and a ceiling-aware damped trend, using observed original first-print values from 2025-07, 2025-09, 2025-11, 2026-01, and 2026-02. I start at latest 99.6, subtract 3.4 pp for regression from an extreme near-ceiling print, subtract 2.0 pp for renewal-cohort volatility, and keep a +0.0 pp net policy/system improvement adjustment because the latest jump may be partly durable, giving 94.2. The 80% interval uses realized first-print dispersion: recent range 28.7 pp and mean absolute adjacent step about 12.9 pp, widened over the six-month horizon and made asymmetric by the 100 percent ceiling.

Counter-consideration: upside outside the interval is limited but would occur if Idaho's February near-100 percent processing reflects a stable automated renewal process and August's cohort remains data-match friendly. Downside outside the interval would require the February result to be a one-off, a manual-heavy renewal cohort, a data-source outage, eligibility-system issue, or a reporting break pushing the first print below 78.4 percent.

Historical mean = (72.6 + 82.9 + 83.2 + 70.9 + 99.6) / 5 = 81.8 percent. Observed adjacent changes were +10.3, +0.3, -12.3, and +28.7 pp, with mean absolute change 12.9 pp. Point calculation: latest 99.6 - 3.4 pp ceiling-regression adjustment - 2.0 pp cohort-volatility adjustment = 94.2. Interval calculation: center 94.2, lower half-width 15.8 pp and upper half-width 5.6 pp, yielding 78.4 to 99.8 after rounding.

Resolution-date note: the canonical ledger target uses 2026-12-15 for the August 2026 first-print row. The official CMS page checked this run confirms the monthly data.Medicaid.gov release vehicle and current monthly-update pattern, but did not expose a separate future-dated August 2026 placeholder; I keep the forecast tied to the ledger date and bind scoring to the first official CMS dataset print.

Review disposition: accepted the reviewer suggestions by clarifying that intervening months were unavailable in the inspected context and by stating that the 80% interval is asymmetric because the series is bounded by the 100 percent ceiling; no required fixes were identified.