Most billers do not understand the use of Box 11 when submitting claims to Medicare. If that box does not contain the correct information it may result in a denial. It doesn’t matter whether the claims are electronic or paper, box 11 must have the correct information in it or Medicare will reject the claim.
Box 11 on the CMS1500 form is labeled as “insured’s policy group or FECA number”. This is confusing to most billers because Medicare doesn’t use group numbers. However, Medicare does use Box 11 to indicate certain situations.
First of all, if Medicare is primary which for most Medicare eligible patients it is, then you need to indicate that by putting the word “none” in this box. The word “none” indicates that there is no other insurance primary to the Medicare policy.
If the patient has an insurance plan that is primary to Medicare then that must be indicated in this box. For example, if the patient’s spouse is still working and they have a group plan through their employer and that group plan is primary to Medicare, that plan would be indicated in Box 11. Now you would think that you would enter the group number of that plan, but not all insurance plans issue group numbers. I was recently told by Medicare that they want the name of the insurance carrier in this box. In my case it was Blue Cross Blue Shield.
Most of the billing instruction manuals I have looked at have this incorrect. They say to leave it blank. But Medicare will tell you different and I’ve seen denials for leaving it blank. Instructions may vary a little from regional carrier to regional carrier but for the most part the regulations are pretty consistent.
Since very few billers still complete the CMS1500 by hand it is imperative that it is determined which field in your practice management system populates that box. That way whether you are printing them out on paper or submitting electronically, the correct information will be in the box.
In our practice management system it is the group number field on the insurance screen. So in my previous example where Blue Cross Blue Shield was prime we had to enter a group number of “BCBS” on the patient’s Medicare policy screen. I know it sounds odd but it populated the fields the way they needed to be and got the claim paid.