Will I lose my pre-approval letter?

You should really discuss the situation with your lender. If you put those costs on a credit card that could afect your credit scrore and you still need to have the needed money for the downpayment but otherwise it probably will not affect you from the info you provided.

I'm sorry to hear about your son's misfortune. Definitely speak with your lender. They will be able to assess any impact that the $3,500 will have on your potential loan. DTI does not seem to be an issue, so the only thing I can imagine it would affect is your down payment and mortgage reserves. Your loan officer is there to try to help you get a loan within the guidelines of the loan program, so just tell them what happened and most likely, you will not have an issue.

Don't be nervous... Just call your loan officer and have them look at your new numbers. It could mean a big difference, it could mean nothing.

Without looking at your complete file, no one here can advise you... Your existing lender has your complete file, so why aren't you calling him?? Purchasing a home or an investment property has different reserve requirements.. Assuming you have sufficient cash reserves in the bank, you should be ok.. but again.. call your loan officer.. they don't get paid unless they can get the loan approved.. if there's an issue, you're paying him to make it happen.. so let him do his job.. I'm a Broker here in Scottsdale AZ and I only lend in Arizona. If you or someone you know is looking for financing options, feel free to contact me or pass along my information. William J. Acres, Lender411's number ONE lender in Arizona. 480-287-5714 WilliamAcres.com