How many usernames do you have? If the answer is more than zero, then it's too many. Remembering which username to use for a particular software system can be as paralyzing as remembering the password. That's why pMD will be getting rid of usernames.
Many systems have replaced the username with an email address. This worked well in the 90s, when most people had a single email address; but now it's ambiguous because everyone has both business and personal addresses - and often more than one of each. Instead, pMD will be using cell phone numbers as a replacement for usernames.
This works because pMD already requires a unique cell phone number for every user, which is used for identity verification and for certain kinds of system notifications. Now the same cell phone number will act as a username for logging in to the charge capture and secure messaging system. Everyone knows their own cell phone number, so this change will remove the need for a "Forgot your username?" link. It's also easier to type a cell phone number than a username on a mobile device, since the numeric keypad has larger buttons than the alphabetic keyboard.
It's exciting to be on the leading edge of a change that will sweep through the software industry. I hope that other software systems take the same approach, since I'm tired of trying to guess my username!