How long does it take for credit score to go back up after a new mortgage?

Several months or even years of timely payments, if you carry too much debt your score will be around 700 if everything is paid on time, you can still getting new credit but the new creditors probably will want proof of your income before approval

Carl.-

It really depends on what else happens with your credit.

A mortgage, or installment loan, will produce more points with on time payments, than a credit card or revolving type loan will.

Keep in mind, many other things effect your score as well.

The number of active accounts, any negative items such as collections, charge offs, or judgments will continue to pull the score down, even as you are adding the positive points.
In addition, your balances in relation to your available credit are included in the scoring as well.

If you have any negative items, work on getting those cleared up too, while making every mortgage payment on time, and your score will be moving in the right direction.