You can change the default behavior in the /etc/security/user file. The first stanza in the file should start:
default:
admin = false
login = true
su = true
daemon = true
rlogin = true
sugroups = ALL
<etc>
To change the values:
(a) backup the /etc/security/user file
(b) change the values
chsec -f /etc/security/user -s default -a maxage=13 -a minalpha=6 minother=2
This will change the default behavior to have the password expire each 13 weeks, and that each password must have at least 6 alpha characters and 2 non-alpha characters.
You can set the values per user in the same way, just provide the account name in place of "default" in the above line
-glenn