Changing your name on your passport is a necessary step if you have changed your name any time recently. If you plan to go abroad, it is very important to remember the fact that if you have had a name change in the recent past, but your passport still uses the old name; you could very possibly run into some serious trouble.
Also, it is very important to ensure that you do this in a timely manner in case you must leave the country for a family emergency, or a business trip. If left unchanged from the prior name, it may be close to impossible to reach the destination that you need to get to.
There are three different scenarios that you may have come into that would be cause for a need to change your name on your passport.
The first scenario is if you received your passport less than a year ago and since then you have had your name changed legally due to a court order or you got married. If this is the case, then you should mail in your current valid US Passport, the (DS-5504) form, which is the actual application for any sort of changes to a passport whether it be a name change or some form of data correction or a limited passport book used for replacement. You will also need the original or certified copy of your marriage license or certificate or the government issued document that shows evidence of any court order with a legal name change under either state or federal law. It may be required that you submit one recent color photo.
The great thing about a simple name change within the last year is that is free of charge unless you require the expedited service. Please use a traceable form of mailing and use a mailing packaging that is of suitable size and provides adequate protection for the documents inside.
When it comes to the photo requirements, they must be printed on photo quality paper and be 2 x 2 inches, or 51mm x 51mm in size. It must have been taken in the last 6 months taken in plain view without any sort of obscurities that would prevent your identification. You should wear your normal daily clothes along with any needed hearing aids, glasses etc. Hats are not permissible unless it is for religious purposes. Regardless though, the entire face must be visible and there may be no shadows casted on top of your face, for whatever reason.
The second scenario is if your passport was issued more than 1 year ago and since then you have had your name changed legally due to a court order or you got married. If this is the case, then you must mail in your current valid US Passport, the completed form (DS-82 as opposed to DS-5504) which is the actual application for a passport. You should NOT use DS-5504. You will still need the original or certified copy of your marriage license or certificate or the government issued document that shows evidence of any court order with a legal name change under either state or federal law. It may be required that you submit one recent color photo if you need to update the photo on file.
You are for the most part applying for a brand new passport. Due to the fact that you are filling out for DS-82, you must be pay the renewal fee involved with getting a new passport which is $140 for the passport and card, $110 for just the passport book, and $30 for just the passport card. Again, please ensure that you use a traceable form of delivery.