Who Is Primary Medicare Or Employer Insurance? 
In most situations the answer to your question is based upon the size of the employer group . If the group has on average 20 or fewer employees then Medicare is the primary payer in a dual coverage situation -LRB- Medicare + group coverage -RRB- . If the group has more than 20 employees then the employer 's insurance coverage is in the primary pay position and Medicare is secondary . This covers the vast amount of situations . As with every government program there are other rules and thresholds that can apply in a variety of other situations to numerous to list here . One that may be encountered by some people is when they or a covered dependent become disabled . In that circumstance , for employers with an average of 99 or fewer employees then Medicare is the primary payer on that disabled person and the employer 's group plan is secondary . For more information or advice feel free to contact me . 