The answer first: between January and April 2026, at least four named payer documents moved prior authorization review between eviCore, Carelon, and in-house teams, and every one of those handoffs reset the portal, the clinical criteria, and the rules for honoring auths approved under the outgoing vendor. BCBS Montana moved Healthy Montana Kids from eviCore to Carelon effective Jan. 1, 2026. Aetna delegated Medicare Advantage home health review in Missouri to Carelon on the same date. Cigna published an eviCore Newly Delegated Services list in Feb. 2026 that took effect March 7, 2026. Independence Blue Cross reissued its UM provider manual in Apr. 2026. If your team is still working from a delegation snapshot taken last year, some of your auth requests are going to the wrong reviewer today.

The 2026 delegation matrix, built only from the payers' own documents

This is the assigned visual and the working tool. Each row is a payer program, its outgoing review path, its incoming vendor, the effective date, and the named source document. This is what a standing per-payer delegation matrix looks like. Yours should have a row for every payer you bill, and a refresh date no older than one month.

Note the direction of the Cigna row. The reshuffle is not a one-way migration to Carelon. Cigna moved additional service lines INTO eviCore review on March 7, 2026, per the list it published in Feb. 2026. Delegation moves in every direction, which is exactly why a static cheat sheet fails.

Four months, four documents, one timeline

What actually breaks in a handoff

The operator to-do list

1. Build the matrix. One row per payer program you bill: current UM vendor, service lines covered, portal, effective date, source document by name.
2. Refresh it monthly. Assign one owner to sweep payer provider notices, newly delegated services lists, and UM provider manuals on a fixed calendar day. The Cigna Feb. 2026 to March 7, 2026 window shows why quarterly is too slow.
3. Capture auth honoring language at every transition. Paste the exact sentence from the payer notice into the matrix row. Ambiguity here is where revenue leaks.
4. Sweep open auths that span a cutover date. Any approval from the outgoing vendor with remaining visits or dates of service after the effective date gets re-verified with the incoming vendor before the next claim goes out.
5. Inventory portal credentials before the effective date, not after. Registration queues back up in the weeks around a cutover.
6. Brief intake and front-end teams. The people keying auth requests need the new routing on day one, not after the first denial batch.
7. Appeal transition denials with the notice attached. A claim denied for no auth, where the auth was issued by the outgoing vendor before the cutover, is an appealable payer-side routing failure. Cite the payer's own effective date.