IF you have a mortgage, VA or otherwise, you cannot just transfer a mortgage/title to another person - the lender has to be involved.
1. THE EASIEST and MOST CONCLUSIVE WAY: You can sell it to him - he will have to secure financing for the entire amount that will clear the mortgage that you currently have - then your loan is completely closed, and he gets the house and the new mortgage / title.
2. CAN YOUR SON ASSUME THE LOAN? A few VA Guaranteed Home loans are assumable but you will have to read your loan documents to see if such a benefit is included in the loan documents and what qualifiers the lender may have added to this "assumable" option to see if your son may qualify.
If he cannot qualify for the assumable loan, if one exist, he has to buy the home from you outright. Those are the only (2) possible solutions and you still have some liability under the assumable option. If neither of those work - you have to sell it to somebody else OR find somebody who does qualify to assume the loan - I would be very leery of the "assumable" because it still leaves you with some responsibility and liability.
This is from the VA link below on assumable VA loans and it is very important because you need to understand exactly where you would stand under this "assumable" option if your son or anybody else can qualify with the lender under an "assumable" option, if the lender even has one - it should be covered in your loan (lender) documents.
Does having a VA loan limit a veteran's right or ability to sell the property?
No. A veteran may sell the property to a veteran or non-veteran at any time. However, if the loan was approved on or after March 1, 1988, and it will be assumed, the qualifications of the assumer must be reviewed and approved by the lender or VA.
When a veteran sells the property to someone who will assume the existing VA loan, is the veteran released automatically from personal liability for repayment of the loan?
No. If the loan was approved on or after March 1, 1988, the lender or VA must be notified and requested to approve the assumer and grant the veteran release from liability. If the loan was approved prior to March 1, 1988, the loan may be assumed without approval from VA or the lender. However, the veteran is strongly urged to request a release of liability from VA.
If a loan closed prior to March 1, 1988 can be assumed without VA's approval, why should a veteran be concerned about requesting and obtaining a release from personal liability?
If a veteran does not obtain a release of liability, and VA suffers a loss on account of a default by the assumer or some future assumer, a debt may be established against the veteran. Also, strenuous collection efforts will be made against the veteran if a debt is established.
How may a veteran obtain a release of liability from VA?
By having the buyer assume all of the veteran's liabilities on the VA loan, and by having VA or the loan holder approve the buyer and the assumption agreement. If the VA loan was approved prior to March 1,1988, the application forms for a release of liability must be requested from the VA Regional Loan Center of Jurisdiction.In most cases, if the VA loan was approved on or after March 1, 1988, the application forms must be requested from the lender to whom the payments are made.
READ your Lender loan documents - TALK TO YOUR LENDER
READ what stipulations you agreed to for the VA Home Loan:
READ about the VA Loan Guaranty Program so you can understand it fully - especially the assumable part if that option exist and where that puts you in the mix.