When you have a Medicare Supplement Insurance policy—commonly known as Medigap—that is endorsed by AARP and administered by UnitedHealthcare, it functions as secondary insurance to Original Medicare. This means Medicare pays its approved amount for covered healthcare costs first, and your Medigap policy pays its share of the remaining out-of-pocket expenses, such as deductibles, coinsurance, and copayments, based on the specific plan you have selected.
The Role of Secondary Coverage in the Medicare System
To understand the dynamic between a Medigap plan and Original Medicare, it is essential to view the Medicare landscape as a two-tiered system. Original Medicare (Part A and Part B) serves as your primary health insurance. When you visit a healthcare provider, the provider submits the claim to Medicare first.
Medicare reviews the claim against its coverage guidelines, pays its portion of the "Medicare-approved amount," and issues a Medicare Summary Notice (MSN). If you have a Medigap policy, the claim is then automatically forwarded to your insurance carrier. The carrier processes the remaining balance based on the federal standardized plan letter (e.g., Plan G or Plan N) you chose when you enrolled.
AARP-endorsed Medigap plans are not "secondary" in the sense that they provide lesser coverage; rather, they are "secondary" in the technical order of operations. They are designed to fill the "gaps" left behind by Medicare, effectively lowering your financial liability for covered services.
Distinguishing AARP-Endorsed Plans from Medicare Advantage
A significant source of confusion for many beneficiaries is the distinction between Medigap plans and Medicare Advantage (Part C) plans. It is vital to clarify that an AARP-endorsed Medigap policy is not a Medicare Advantage plan.
Medicare Advantage plans replace your Original Medicare coverage entirely; they are private plans that act as the primary insurer. If you are enrolled in a Medicare Advantage plan, you cannot use a Medigap policy alongside it. Medigap policies can only be purchased and used by individuals who have Original Medicare.
Because AARP-endorsed Medigap plans function as secondary coverage, you generally retain the freedom to see any doctor or specialist in the United States who accepts Medicare. There are no narrow provider networks to navigate, which is a primary reason many beneficiaries choose this structure over the restricted networks often found in Medicare Advantage plans.
How AARP-Endorsed Medigap Plans Process Claims
The administrative efficiency of AARP-endorsed plans relies on an automated system known as "crossover." In most cases, you do not need to file a claim yourself. When your healthcare provider submits a bill to Medicare, the system automatically recognizes that you have a Medigap policy on file.
- Provider Submission: The physician or facility sends the bill to the Medicare Administrative Contractor (MAC).
- Medicare Payment: Medicare processes the claim and pays the primary share.
- Crossover: The system transmits the claim details to UnitedHealthcare, the entity that administers AARP-endorsed insurance products.
- Secondary Payment: UnitedHealthcare calculates what your policy covers and pays the provider directly for the remaining coinsurance or deductible.
- Statement of Benefits: You receive an Explanation of Benefits (EOB) from your Medigap provider detailing what was paid on your behalf.
This "crossover" process prevents you from having to handle paper claims, ensuring that your secondary insurance works seamlessly in the background.
Standardized Benefits and Plan Options
All Medigap policies, including those endorsed by AARP, are regulated by federal and state governments. Because these plans are standardized, a "Plan G" from one company must offer the same basic benefits as a "Plan G" from another. However, the premiums, underwriting practices, and customer service experiences can vary significantly between insurance carriers.
The following table illustrates the general coverage areas that typically define how Medigap plans function as secondary coverage:
| Benefit Category | Original Medicare (Primary) | Medigap Plan (Secondary) |
|---|---|---|
| Part A Hospital Deductible | You pay | Plan pays (or contributes) |
| Part B Coinsurance/Copays | You pay 20% | Plan pays 20% |
| Part A Hospice Care | Medicare covers | Plan covers copay |
| Blood (first 3 pints) | You pay | Plan pays |
| Skilled Nursing Facility | Medicare pays share | Plan pays coinsurance |
| Foreign Travel Emergency | Not covered | Plan pays 80% (up to limit) |
Note: Coverage details are subject to the specific plan letter chosen. Benefits are mandated by federal law, though availability may vary by state.
Prerequisites for Enrollment and Eligibility
To enroll in an AARP-endorsed Medigap plan, you must meet specific eligibility criteria. First, you must be enrolled in both Medicare Part A and Part B. If you are still in your Initial Enrollment Period (the six-month window that begins the month you are 65 or older and enrolled in Part B), you have a "Guaranteed Issue" right. During this time, insurance companies cannot deny you coverage or charge you more due to pre-existing health conditions.
If you apply for an AARP-endorsed plan outside of your initial enrollment window, you may be subject to medical underwriting, depending on your state's regulations. In some states, insurers are required to offer open enrollment periods beyond the federal mandate, but in others, your health history could lead to higher premiums or a denial of coverage.
Common Misconceptions Regarding AARP-Endorsed Coverage
A frequent misunderstanding involves the assumption that AARP is the insurance provider. AARP is an advocacy organization that licenses its name to UnitedHealthcare, which designs, underwrites, and manages the policies. This distinction is important for beneficiaries to understand when troubleshooting issues with their coverage.
Another misconception is that Medigap covers prescription drugs. It does not. AARP-endorsed Medigap plans are designed to pay for medical costs (Part A and Part B gaps). To cover prescription medications, you must enroll in a standalone Medicare Part D prescription drug plan. Having a Medigap plan does not prohibit you from carrying a separate Part D plan; in fact, it is common practice to combine the two to create a comprehensive secondary insurance shield.
Addressing Troubleshooting and Administrative Hurdles
Even with an automated crossover process, errors can occur. If your provider bills you for an amount that you believe your Medigap policy should have covered, take the following steps:
- Verify the Provider: Ensure the provider is a Medicare-participating provider. If they "opt out" of Medicare, your Medigap plan will not provide secondary coverage for their services.
- Review your MSN: Check your Medicare Summary Notice to see if Medicare denied the claim. If Medicare doesn't pay, your Medigap plan won't pay either.
- Contact Customer Service: Call the number on the back of your AARP-endorsed member card. Provide them with the claim number from your provider. They can verify if the claim was received and why it may have been rejected.
- Submit Manually: If the crossover did not trigger correctly, you can request that the provider resubmit the claim or you can file the paperwork directly with your Medigap carrier, attaching a copy of the original Medicare EOB.
Expert Guidance for Policy Management
As a policyholder in 2026, you should perform an annual review of your health status and coverage needs. While standardized plans remain the same, premiums can change annually due to inflation, medical loss ratios, and state insurance department adjustments.
If you are considering a switch or a new policy, ensure that you understand your "Guaranteed Issue" rights. Never cancel an existing policy until your new coverage is officially confirmed and active to avoid any gaps in your secondary protection. Always maintain a digital or physical file of your current plan documents, specifically your Summary of Benefits, to resolve any discrepancies at the point of service.
Frequently Asked Questions
1. Does AARP offer a Medicare policy that pays before Medicare? No. By law, Medigap policies (including those endorsed by AARP) are supplemental, meaning they must pay secondary to Original Medicare. They cannot function as primary insurance if you are eligible for Medicare.
2. Can I keep my AARP-endorsed plan if I move to a different state? Generally, yes. These plans are portable across the United States. However, because premiums and plan availability can vary by state, you should contact the plan administrator to update your address and determine if your specific plan remains the most cost-effective option in your new location.
3. Will my AARP-endorsed plan cover my spouse? No. Medigap policies are individual contracts. Your spouse must apply for their own separate policy based on their own Medicare eligibility and underwriting status.
4. Does the "AARP" endorsement affect the cost of the plan? The AARP endorsement is a brand licensing agreement. While these plans are generally competitive, the premium is determined by the insurer (UnitedHealthcare) based on factors like your age, gender, zip code, and tobacco use, regardless of the AARP brand association.
5. What happens if I lose my Medicare coverage? If you are no longer enrolled in Medicare Part A or Part B, you are generally no longer eligible for a Medigap plan. You must notify your insurance carrier immediately to cancel your policy, as it can no longer function as secondary insurance.
Next Actions for Policyholders
If you currently hold an AARP-endorsed Medigap plan, your primary task is to ensure your healthcare providers have your most recent insurance information on file. Confirm that both your red, white, and blue Medicare card and your AARP-endorsed member card are in the provider's billing system. If you are nearing age 65 or are currently within an enrollment window, review the standardized plan options available in your state to ensure your chosen letter-plan (e.g., G or N) aligns with your anticipated out-of-pocket budget.
