Which USCIS lockbox applies to a form I-485 filed by an spouse?

Use the same lockbox as original filing but check online because they do seem to change this fairly regularly.

Before sending your package to USCIS, make sure that all the forms you have completed are the current acceptable edition. The current acceptable edition can be found under the Edition Date section listed on each form’s webpage.
You can also find the edition date at the bottom of the page on the form and instructions. For each form that you are submitting, make sure that all pages are from the same form edition. If any of the form’s pages are from a different form edition, we may reject your form. Watch USCIS Forms: Download the most recent version! to see how to ensure your form is acceptable.
For additional guidance on filing paper-based forms at the Lockbox and how to avoid or correct common errors before you file, please visit the Five Steps to File at the USCIS Lockbox webpage.
Where you file your Form I-485 depends on your eligibility category. Review the information below to see where you should file your application.
Applications that are not mailed to the correct address may experience processing delays.
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Family-Based Adjustment
T Nonimmigrant, U Nonimmigrant, or Violence Against Women Act (VAWA) Self-Petitioner (including under the Cuban Adjustment Act (CAA) for Abused Spouses and Children and the Haitian Refugee Immigration Fairness Act (HRIFA) for Abused Spouses and Children)
Cuban Adjustment Act (CAA) (Not eligible under the Act for Abused Spouses and Children)
Amerasians, Widow(er)s of a U.S. Citizen who Died within the Past 2 Years, Special Immigrant Juveniles, and Special Immigrant Armed Forces Members
Certain Special Immigrant Employment-Based Categories and Employment-Based Categories with a Pending or Approved Form I-140
Employment-Based Categories Filing Form I-485 Concurrently with Form I-140

Investor Filing Form I-485 with or based on Form I-526 or Form I-526E
If you are filing:
Then mail your form to:
* With Form I-526, Immigrant Petition by Standalone Investor;
* With Form I-526E, Immigrant Petition by Regional Center Investor; or
* Based on an approved or pending Form I-526 or Form I-526E. You must include a copy of the notice showing we accepted or approved your Form I-526 or I-526E.
USCIS Dallas Lockbox
U.S. Postal Service (USPS):
USCIS
Attn: I-526/E
P.O. Box 660168
Dallas, TX 75266-0168
FedEx, UPS, and DHL deliveries:
USCIS
Attn: I-526/E (Box 660168)
2501 S. State Highway 121 Business
Suite 400
Lewisville, TX 75067-8003

You can find applicable filing address at USCIS website, at Form I-485 page. There is a section called “Where to file.”