This would be a great question to post at Ask USAA! I looked through there and don't see that specific question asked before.
My take is:
The prevaling thought seems to be around 720, but I think if you want the best interest rate you will want to do these three things:
1. Score above 740
2. 20% or more down payment
3. Shop around
You should call one of the USAA reps for financial advice. I did so a few years ago (same situation, rebuilding credit) and I learned a lot from them. It was completely free, too (which was my favorite part).
Sorry for my delayed response, as I am not an expert in this area, I wanted to make sure I tracked down a good answer! Here is what our expert recommends:
There are 2 important aspects of credit score when it comes to mortgages. The first is the minimum score needed for loan approval. The second is the effect credit score has with relation to interest rate, discount points, mortgage insurance, and in some instances homeowners insurance. As a general rule of thumb, every layer of risk results in a layer of price. In addition to credit score, examples include property type (a condo versus a single family detached home), down payment (5% versus 10% or 20%) etc.. Depending on the lender and/or the loan product, these impacts can be significant. It’s always important to ask a lot of questions when shopping for a mortgage loan. You can find much more information about building credit here.
I also want to second Jatter's recommendation and encourage you to contact our team of Financial Advisors here at USAA who can give you advice based on your specific situation and needs. They can be reached at 800-771-9960.
Thank you for your questions and congratulations on recovering your credit!!