You do a Homestudy Addendum.
A homestudy addendum is different from a homestudy update.
- Costs a lot of money (the same as you usually pay for a homestudy because each time your file a new I600A that's what you have to get, a HS UPDATE.)
- Requires you collect all that stuff again, physicals, etc. for the Social Worker
- Requires that you refile your I600A, even if the I-171H attached to it is still valid, which includes paying all the fees to USCIS that may apply to such a filing, and switching to I800A if you're out of I600A renewals
- And is titled UPDATE
You don't want to do a HS Update when all you need is to report changes. You do that with a:
- Is an add-on to your most recent homestudy
- Costs a lot less (for us it was a $150 addendum VS a $600 Update)
- Does not require you to collect anything (no forms, fingerprints, letters, etc.)
- Does not require you to refile anything with USCIS. You simply hand it in and they process it (send it to your consulate office, which, for China adoptions, is Guangzhou, China) for free.
- And is titled ADDENDUM
Make sure you know which one you need because your HS agency will give you what you ask for (because it's more $ for them), but they fully understand the difference and should be able to do both an UPDATE and the ADDENDUM. Make sure that your HS agency titles the addendum as ADDDENDUM or you will have trouble with USCIS.
Try to hand in your addendum at least a month before you leave the US on your adoption trip.
Make sure to impress upon USCIS that they need to forward this update on to your consulate office.
Also, if you request a child 2-4 years old (for example) and you accept a referral of a child who is just 4 at the time of referral, you will need an addendum to state that you can handle a child from 2-5 years old, or USCIS will not let you travel. Nit-picky to the end!
Good luck, and post any questions to the comments.