Hello @salwaebrahim -- I would like to add my welcome to Connect along with @lisalucier. It's always difficult when you have to deal with insurance claims that are denied. You do have certain rights though so it pays to be your own advocate. It's good that Mayo is working with the insurance company so hopefully it will be resolved for you. Here are a couple of links I found that may be helpful just in case:

HealthCare.Gov - How to appeal an insurance company decision:
-- https://www.healthcare.gov/appeal-insurance-company-decision/appeals/

National Public Radio - Patients Often Win If They Appeal A Denied Health Claim
-- https://www.npr.org/sections/health-shots/2014/04/14/302547851/patients-often-win-if-they-appeal-a-denied-health-claim

John