When you can first sign up for Medicare, it is advisable to sign up for Part A. Given that the current health coverage is coming through your employer, odds are that you or your spouse has paid payroll taxes to Social Security for at least forty quarters (ten years) through the employer. This qualifies you for premium-free Part A, meaning you have only to gain by holding the additional coverage.
You can also hold Part B coverage or choose to delay it until you lose the health coverage or employment. Should you choose, you can still sign up for Medicare Part A and Part B when you become eligible, even if you have coverage from your employer. The size of the company may determine how that works.
If you receive a service outside of your employer plan’s network, neither the group health plan nor Medicare will pay in full for your service.
Multiple Insurance
For people with multiple forms of insurance, each is referred to as a payer. The primary payer pays first for your medical bills and sends the remainder of the bill to the secondary payer. The first pays up to the limits of its coverage, and the second only pays if there are costs left over. The second payer may not cover the rest of the costs. You may need to enroll in Part B before your employer’s insurance will pay.
Employer Has 20+ Employees
For large companies, the employer group health plan is often the primary payer. The healthcare provider then sends the remainder of the bill to Medicare, which pays based on the amount the group health plan paid, the group health plan allowed, and the provider charged. You are responsible for any costs not covered by the health plan or Medicare.
Employers with 100 or more employees have large group health plans. Medicare pays second after large group health plans.
Employer Has Fewer Than 20 Employees
For smaller companies, Medicare often pays first. If the employer sponsors a group plan with other employers in what is called a multi-employer plan, Medicare will pay second. If any of the other employers in the multi-employer plan has more than twenty employees, Medicare will pay second.
