Yes you can. You might need to inform Soc Sec you do not want part B. Part A has no premium of those with enough work history. I will not call it free b/c we paid that medicare tax and you still are paying it as long as you work. When you stop working (by choice or otherwise) apply for part B and look into supplimental ins or Advantage plans. Also, if you have a working spouse, insurance from them could qualify. One more thing: I assume your employer has 20 or more employees, making it credible coverage.