Where the numbers come from
Every statistic on this site traces to a public source, and insurer-specific numbers only go live after human verification against the source document. Here’s the whole pipeline.
California IMR: 42,749 published decisions (2001–2026). CMS-0057-F: 15 insurer rollups plus 277 contract/plan rows, for 292 data rows in the current CSV.
Provenance hierarchy: the linked agency or insurer disclosure is the upstream record; Coverage Rights normalizes fields, preserves source URLs and scope notes, and computes labeled aggregates. If a compilation conflicts with its source, the source controls and the compilation should be corrected.
Verification process
Collect
Metrics are pulled from insurer disclosure pages, state databases, and CMS files — each row records its source URL and collection date.
Stage
New and changed rows land in a pending-review queue. Nothing publishes automatically.
Verify
A human checks each row against the source document before it’s marked verified and shown on insurer pages. Unverified figures are labeled SAMPLE or hidden.
Correct
Spot an error? Email data@coverage-rights.com with the source and we’ll fix or annotate within a week.
Sources
Denial rates, appeal outcomes, and turnaround times from insurers' required CY2025 disclosures. The current compilation has 15 verified insurer rollups and 277 contract/plan rows across 7 insurers; the CSV contains 292 data rows in total.
42,749 published California external-review decisions (2001–2026). We publish derived counts and rates, plus selected deidentified decision excerpts and the source reference IDs needed to trace them. The public JSON download contains aggregates, not the record excerpts.
Contract-level prior authorization volumes, denial rates, and overturn rates from CMS public data releases.
Named-insurer findings on denial patterns (e.g., skilled nursing and post-acute care denial studies). Cited and paraphrased, never reproduced.
Medicare Advantage prior-authorization statistics — including KFF's finding that 11.5% of denied requests were appealed and 80.7% of appealed 2024 denials were partially or fully overturned — cited with year, cohort, and attribution.
Data dictionary
| Field | Definition and denominator |
|---|---|
| rollup | One insurer-level summary row. It may be insurer-published or transparently computed from posted plan/contract rows; the row's note states the method and scope. |
| contract / plan row | One source-linked CMS-0057-F disclosure row for a contract, state plan, or issuer. A repeated parent insurer does not make the rows interchangeable. |
| PA denial rate | The percentage of reported prior-authorization determinations denied in the source's stated population and track. Scope can differ by line of business and source. |
| appeal overturn rate | The percentage of resolved appeals approved after the initial denial, when reported. Its denominator is appeals, not all prior-authorization requests. |
| IMR decision | One published California DMHC Independent Medical Review determination in the source corpus. Counts describe cases that reached and completed that program. |
| overturned | The independent reviewer reversed the plan's denial in the published determination. It is a historical outcome, not a predicted probability for another case. |
| excerpt / reference ID | A selected deidentified passage from a published determination plus its source reference identifier. Excerpts appear on evidence pages; the JSON download remains aggregate-only. |
Download the data
Coverage Rights’ compiled dataset files and original field arrangement are offered under CC BY 4.0. Attribution is required; cite “Coverage Rights, coverage-rights.com.” A link is appreciated as the practical form of attribution, not an additional license condition. Underlying public agency and insurer materials remain subject to their own source terms.
CMS-0057-F: 15 insurer rollups plus 277 contract/plan-level rows across 7 insurers with collected contract detail; every contract row carries its source URL. External review: aggregate outcomes from 42,749 published California IMR decisions (2001–2026) by treatment, condition, and denial type. Selected deidentified excerpts and reference IDs appear on evidence pages but are not part of the aggregate JSON download. Developers: the same corpus is queryable live via our MCP server.
Citation discipline
Generated appeal letters cite only from our rights corpus — statutes and regulations stored with their citations, each sourced from primary law — and statistics only from verified metric rows. The generator is structurally prevented from inventing citations: if it isn’t in the corpus, it doesn’t go in the letter.