any advice on buying a new home and keeping your current (10 years left on mortgage) as a rental property? how much $$ should you have in reserve?
I've done this twice now. My original home I bought in 2003. Market crashed in 2008. In 2011 I bought another home, I kept the 2003 home because it was still upside down and I didn't want to unload it for a loss, so I rented it out. Last year I bought a new home, I turned my 2011 home into a rental, so now both rentals and my new home.
I would say you should have 6 months worth of mortgage payments in the bank for reserve (i.e. you could pay your mortgage for 6 months even if it stays empty).
The most important thing to do is research on rental comps in your area. How much could you rent your home for? Will that cover your current mortgage, insurance, taxes, etc? Also note that when you convert your home to a rental, you will lose a lot of the tax benefits. You will no longer be able to deduct your mortgage interest. Any profit you make on the home becomes taxable income.
Next, research how hot is the rental market in your area. Are there a lot of rentals available on the market? Few? How many days/months does the typical rental stay on market until it gets filled?
For myself, I live in California, the rental market is extremely strong here. My 2003 home I have rented to 4 different families in the past 14 years. Each time it took 2 weeks or less to get a new lease signed. For my 2011 home I have a tenant in there from 2016, so fairly new, it also took less than 2 weeks to get a lease signed.
Bottom line......if you have money in the bank to pay the mortgage for a few months (I recommend 6), and the rental market is good in your area, then I think it's a good move. Conversely, if rentals don't really do well in your area, or you don't have much of a financial cushion, then probably you would be better off selling your home (assuming profit), and putting the money into your new home to bring down your monthly payments.