This is a legitimate number from a legitimate contractor called "the social service co-ordinator dept"  that works for many different health insurance providers.
If you have any doubts simply call your health insurance provider as you normally might for any other reason and ask for the social service co-ordinator through them, as I did. They are apparently unaware of their bad rep on this and similiar forums. They will help you get your medicare payment paid for by medicaid or from some other agency in your state. That is what they did for me. Now I get my full SSDI without the medicare deduction. Check it out yourself but go through your insurance provider to be safe and sure.

For all of you who posted your experiences, may I extend my deepest appreciation!

I also received a call.  They said they were offering coverage to pay medical costs not covered by medicare.  They thought I was my 86 year old mother.  They are part of a crime ring that includes a the Jamaican Lottery scams.  They prey on our seniors because they know they are more trusting and often are developing dementia.  They have a strong group in Jamaica, Florida, Las Vegas and in North Carolina.  They sell your phone numbers to each other.  Since I became my mother's conservator I am inundated with scam letters. Calls have almost stopped since I answer, tell them off and then hang up.  My mom's email was loaded with scams too.

I got three calls from this number three days in a row, first two I let go to my answering machine but there was no message left. Then on the third day I answered it and said hello twice and there was no response, just silence.

I have been receiving calls with no caller ID, which I do not answer....this has been going on for about a month, no message left... this morning, after getting 2 such calls, 45 mins later I received  a call from this  number, again no message..... I am on Social Security and Medicare, have good insurance, is the Government selling our numbers.?..I am on the "Do not call" list as well. This is very annoying