If you answer or press any button, they then know it's a working number.  If I happen to have my phone by me, I check the #, turn it on, and immediately turn it off.  Otherwise, I let it ring.

The MED caller is listed as being from Eugene, OR this time!  Good Golly!!  

OK, so we're back to the MED calls offering the medical alert thingy, free coupons, whatever.  It's a scam, a shakedown,  phishing for information.  So, don't respond.  

And, yes, next month it's a new telephone number because once in a blue moon, someone out here is going to take the bait and offer up personal information.  

And, no, under the these circumstances, it's unlikely the gov. is going to chase them down.  Waste of time and money AND they're probably not easy pickings, i.e., they are not calling under someone's Friends and Family Plan,
etc.  :-)