303-664-1673

I just received a call from this number on my cellphone, no message left and when I called back number was disconnected.  I do not owe any outstanding bills, so not sure it is a bill collector?? wouldn't they leave a message ?

I received a call from this number but when I called it back the number was disconnected

I recieved a call from this number, It appears to be an internal line for a Kaiser Permanente facility

Kaiser Permanente - Rock Creek Neurology Department

I called back today and it was disconnected.

I believe it is Kaiser Rock Creek Neurology but they were unable to confirm it is their number.  I was told by Kaiser Rock Creek Neurology that they don't normally leave a message if they call you to say their is an appointment available.  And since it is a trunk line they are using to call you, you apparently cannot call them back on that line.  You must answer it while it is ringing to speak with them.  If the phone has stopped ringing by the time you get to it, you are out of luck and the appointment slot goes to someone else.