One of the big benefits to real estate investing is the tax deductions, primarily depreciation.

Congrats on acquiring 2 rental properties within such a short period of time.Having a conversation with a CPA as a new real estate investor might be helpful as you can be aware of what is deductible / non-deductible along with having an overview of the tax laws that are unique and specific to real estate.Best of luck!

So if I'm looking to hold long term, than I'll lose the deductions in later years?

Just because you paid off the mortgage and do not have interest deduction you still should be capturing depreciation on the asset. what also needs to be answered is, could you take those monies and put it in a better cash-flowing investment?

If it's a 2-4 unit it requires 15% down.If you buy as an investment you get the benefit of the scheduel E deductions and can still add your son to title. 

I'd like to move to ACH with recurring auto-deduct, but have others solved for our situation? 

Mortgage makes more sense because of the tax deduction, more leverage to buy more houses.

How did the deduction schedule work?

Costs vary widely, and for a single property you want someone who's done Indiana STRs before and knows the local nuances.If you're planning to hold long-term and this is your only major deduction, it usually makes sense.

First, evaluate your income bracket to determine whether the accelerated deductions will provide meaningful tax benefits.