Is Medicare Always Primary Insurance? 
There are some situations when Medicare is not primary . This usually happens if you 're currently employed and have coverage under your company where they are primary . In these cases it is important to watch for your EOB -LRB- Explanation of Benefits -RRB- from your insurance companies , because many medical billers are so used to billing Medicare first , that they will automatically do that and Medicare will deny the claim because of it and if you do not catch it in time , you could end up paying the bill the deadline for filing in a timely manner has lapsed . 