Re:
In my experience, $20s are universally available, $10s are available maybe half the time. The only way to get a $10 bill is to select a withdrawal amount not divisible by 20. Even then, it's a crapshoot what you get. Sometimes, withdrawing $150 will give you 5 $20s and 5 $10s, but more often you get 7 $20 and a single $10 bill.
I'm 44 years old and have never seen a $5 bill from an ATM.
Once in Hawaii, I withdrew $200 and got 4 $50 bills. (????) Those were a pain in the rear to get people to accept. I felt sorry for the Japanese tourists who got those and didn't realize why their money was no good at the ice cream stand.
I've only seen $100 bills in Vegas and at the machines in 7-Eleven that can cash government and payroll checks.