An organization that provides health coverage for employees of credit unions in Maine is suing an arm of Elevance Health over how it handled a claim for a stem cell transplant for a plan participant with blood cancer.

The organization, the Board of Trustees of the Maine Credit Union League Insurance Trust, has accused the Elevance unit, Anthem Health Plans of Maine, of delaying consideration of the prior authorization request and the final claim in a way that cost the plan $706,402.86 in reimbursement for the transplant.

The complaint shows how an employer plan goes about handling a conflict over a stop-loss claim, and an exhibit filed with the complaint provides an example of a stop-loss claim audit summary letter.

Representatives for Elevance were not immediately available to comment on the case.

The case: The Maine Credit Union League Insurance Trust operates as a multiple-employer welfare arrangement, an association health plan and a voluntary employee benefits association. Anthem served as both the administrator for the league's plan and the provider of stop-loss insurance for the plan over a five-year period that ended in March.

For the 2022-2023 plan year, the stop-loss policy had a "specific attachment point," or stop-loss deductible, of $240,000.

The patient who had the transplant first applied for prior authorization for the procedure in August 2022 and accumulated enough bills to reach the specific attachment point by November 2022.

The request was approved in December 2022, the patient had the transplant in January 2023, and claims for about $2.1 million in transplant-related bills were submitted in March 2023.

The plan received a notice about a claim billed for more than $1 million in March 2023.

The stop-loss claim was paid in April 2023.

"Under the stop-loss policy, if a claim was received, adjudicated, and paid by Anthem in a plan year, it counted towards the specific stop-loss limit for that applicable plan year," according to the insurance trust.

Anthem did not tell the insurance trust about the preauthorization request or the approval of the request, and "Anthem took no substantive action with respect to the claim until March 31, 2023, which was conveniently the last date of the 2022-2023 stop-loss policy year," the trust says.

The insurance trust says that, because of the lack of communication, it was unaware that getting a stem cell transplant bill for the patient with cancer was a sure thing. It agreed to a renewal that included a $900,000 "laser," or exclusion, for the transplant.

The insurance trust says it received only $985.611.21 in stop-loss reimbursement from Anthem because of the claim-processing delay and the laser.

If Anthem had paid the claim in March 2023, rather than "slow-walking" the claim and paying it in April, the trust would have received an additional $706,402.86 in additional reimbursement, even with the $900,000 laser, according to the audit summary letter.

The insurance trust is accusing Anthem of breach of fiduciary duty under the Employee Retirement Income Security Act, breach of duty of good faith and fair dealing and breach of contract.