How do I interpret "Primary Residence?" IRS seems vague :(

[Michael H.]

Hi folks, I'm purchasing a condo in San Juan, PR as my Primary Residence, so obviously the bank and the IRS expect me to live in that condo for "the majority of the year." I thought the IRS would be more specific by saying something like, at least half of 365 days, or provide more details under varying circumstances (as I'll explain, below). This is the heading of a NY Times article: "Defining your Principal Residence for 'Tax Purposes' isn't always simple." Why?

I'd basically like to spend at least over 6 months in my primary residence in Puerto Rico, and then the rest of the year in the states  (rent or stay w/ relatives). Does this situation seem fine for tax/loan purposes?

Here's my scenario - Let's stay I start making payments on the loan starting in September of 2017.  The last day of the calendar year is December 31st, 2017. So within this time period, would my obligation be to live in this condo for at least more than half of the time period between September and December 31st of 2017?

Ideally, I want to live in this condo for the minimum amount of time required for me to satisfy the "Primary Residence" requirement, and the rest of the time, air bnb the unit out.

I'm trying to avoid any potential issues with the bank and the IRS.

Anybody here have some helpful insight?

Thanks! - Michael