Yes, you do need to report it, you just don't report it on Schedule E. It is a Not-for-Profit
Rental. See below for a link to Pub 535. It does not address the statement, " I ran across this answer that says you don't have to report rental income if it's less than the mortgage interest & property taxes." Some of it applies to hobby income, such as cost of goods sold.
You can deduct your mortgage interest and property taxes on your second home up to allowable limits.
Not-for-Profit activities start on page 7. https://www.irs.gov/pub/irs-pdf/p535.pdf
Gross income from a not-for-profit activity includes the total of all gains from the sale, exchange, or other disposition of property, and
all other gross receipts derived from the activity.
Gross income from the activity also includes
capital gains and rents received for the use of
property that is held in connection with the activity.
You can determine gross income from any
not-for-profit activity by subtracting the cost of
goods sold from your gross receipts. However,
if you determine gross income by subtracting
cost of goods sold from gross receipts, you
must do so consistently, and in a manner that
follows generally accepted methods of accounting.
Limit on Deductions
You can no longer claim any miscellaneous itemized deductions. Miscellaneous itemized deductions are those
deductions that would have been subject to the
2%-of-adjusted-gross-income limitation. You
can still claim certain expenses as itemized deductions on Schedule A (Form 1040).
Deductions you can take for personal as well as
for business activities are allowed in full. For individuals, all nonbusiness deductions, such as
those for home mortgage interest, and taxes may also be deducted. Deduct
them on the appropriate lines of Schedule A
(Form 1040).
