This is the EXACT same thing that happened to me from this number.  
Don't sit there and say the number doesn't match because YOU called me!
Morons.
X6b8

Received same call from 877-834-3237, I did not answer, and then I called the number, I received a Recorded Message "Thank you for Returning Our Call, However I do not recognize the number you are calling from"  and at that point, I hung up.

Like Carol on 5 Sep 2012 (listed above) I too have Humana, and have requested them never to Call, however, they continue to in 2012.  And in 2011, Humana called over 33 times, from numerous different numbers.  I shall drop Humana in 2013

nuisance call      apparently from  an alien

Look, people, wise up. If you don't recognize the number and it isn't on your contact list, DON'T ANSWER THE DAMN THING!!! If you have Sprint, punch *2 and ask them to block the number. They will do it for up to 50 numbers, and, if you want, YOU can do it yourself online by going to My Sprint. Don't have Sprint? Well then, put the number on your contact list, assign it "no ringer" or "silent." You may occasionally get a voice mail alert from these idiots, but they hardly ever leave a message, just a few seconds of silence, which beats having to mess with their constant harrassment. Oh, yes, many other carriers are beginning to offer a blocking service, SO FIND OUT ABOUT YOURS!

It may be Humana Insurance but nothing identifies them because all it says is 800 Service.  If it is Humana, they have done this before and unless my husband and I both talk to them, the calls just keep on coming no matter how many times I have told them that I am not interested.  I have never been harassed from an insurance company like this before and my husband refuses to call them back.  I just screen the calls and document them but they don't leave a message most of the time.  I am sick of all these calls and these and many others just keep calling and there doesn't seem to be anyway to stop them.  Forget about the Do Not Call Registry, it doesn't work.  Of course, it could be Rachel from Card Member Services and they never give up either.

i have humana insurance and they are not supposed to call me i requested  that they never do that and yet here we go again.but thanks for telling me who the heck it was now i won,t call back or anwser that number.

I have no time for these people and they are nothing but pests.  I don't want calls from any insurance company, let them send an email.

They finally left a message.  It's Humana Insurance, calling my wife to give her some Medicare-related information.

I can't identify the caller.

They left no message.  I called back, but I got an automated service that says "Thanks for calling back" and that they do not recognize the number I am calling from.  They asked me to key in my phone number, which I did, but they still could not find me in their database (even though they called me first).  At this point they cycle back to the "I don't recognize the number you are calling from" and we go through the same routine like a broken record.

Wiki Phone Directory says "In Service since 1998-04-04" and has no additional data.

They never identify who they are or what they want.  I am unsure what to think of this caller.