What Is Medigap
Medigap is a private supplemental insurance policy sold by insurance companies to cover the gaps in Original Medicare coverage. These gaps include Medicare Part A deductibles (currently $1,676 per benefit period), Part B deductibles ($240 annually), copayments, and coinsurance. Unlike Medicare Advantage plans, Medigap policies work alongside Original Medicare to reduce your out-of-pocket costs.
When you have Medigap and receive care covered by Medicare, your claim goes to Medicare first. Once Medicare processes it and generates an Explanation of Benefits (EOB), your Medigap insurer receives that claim and pays their share of the remaining balance. This secondary coordination is critical when you're fighting a denied claim, because you may need to appeal to both Medicare and your Medigap carrier simultaneously.
Why Medigap Matters for Claim Appeals
Medigap significantly complicates the appeals process for denied claims. When Medicare denies a claim due to lack of medical necessity or missing prior authorization, your Medigap insurer will also deny their portion. You cannot appeal to Medigap alone; you must first resolve the issue with Medicare because Medigap only covers costs Medicare approves.
Each state regulates Medigap differently. States like New York and Pennsylvania impose stricter requirements on how quickly Medigap carriers must process claims and respond to appeals. If you're appealing a claim, check your state insurance commissioner's office for specific timelines. The federal standard allows 30 days for initial internal appeals, but some states mandate faster responses.
Understanding your Medigap policy type matters too. There are 10 standardized Medigap plans (A through N), and coverage levels vary. Plan G covers more out-of-pocket costs than Plan A, which affects how much you personally owe if a claim is partially denied.
Medigap and Prior Authorization Requirements
Medigap itself does not issue prior authorizations. Medicare determines whether prior authorization is required for a specific procedure or service. However, many Medigap carriers now review claims for prior authorization compliance. If your provider obtained the required authorization from Medicare but it was coded incorrectly or expired during your course of treatment, Medigap may initially deny their portion.
When appealing, request the original prior authorization document from both Medicare and your Medigap insurer. The appeal should include proof that authorization was obtained before the service date and that the authorization covered the specific procedures billed.
Internal and External Appeals with Medigap
Most Medigap carriers allow one internal appeal level. File this within 60 days of your denial notice. The internal appeal goes to a different reviewer than the person who made the initial denial. Your submission should include medical records supporting medical necessity, the original EOB from Medicare, and a written explanation of why you believe the claim should be covered.
If the internal appeal is denied, you can request external review through your state's insurance commissioner or department of health. External review is binding and typically takes 30 to 60 days. States vary in whether external review covers all Medigap denials or only those related to medical necessity determinations.
How to Read Your EOB with Medigap Coverage
- Medicare processes first and shows their approved amount and what they pay on the EOB
- Your Medigap EOB arrives separately and shows what they pay based on their policy terms
- Compare both EOBs to verify no claims fell through the gaps, especially high-cost procedures
- If either carrier denies, the other will also deny their portion automatically
Common Questions
- Can I appeal a Medigap denial without appealing Medicare first? No. Medigap only covers what Medicare approves. If you want to challenge a denial, you must file an appeal with Medicare. Once Medicare reconsiders and issues a new decision, Medigap will reconsider their denial accordingly.
- What happens if my Medigap plan terminates mid-year? You lose secondary coverage immediately. Claims submitted after termination will only be processed by Medicare. Some states require Medigap carriers to notify you 30 days before cancellation, but this varies. Check your state's regulations.
- Does my Medigap plan cover claims from out-of-network providers? Only if Medicare covers the provider and service. Medigap follows Medicare's network rules. If Medicare denies an out-of-network claim, Medigap will too, regardless of your Medigap plan type.