Phone Questions

Hi!

Couple questions on phones in the DR:

1.  I intend to bring my unlocked iPhone 6s (currently have Cricket month to month) and convert to Claro or whomever else is recommended.  What does the forum recommend for international calls, a calling card or an international plan or is something else better?

2.  I will be a retiree on Social Security.  The SSA requires 2 forms of security to log in, a password and a phone security code they send you.  Here in the USA it's not a biggie, even when you change phone numbers.  They just mail you at your home of record a different security code and you use it to change your phone number on their records.  However in the DR, they won't be able to do it.  I'm concerned in not being able to contact the SSA in the event of an issue.  Any suggestions?

Thanks so much in advance!!

Rob