Hello,
-I am the "emergency contact" for my aunt who has recently been placed in a nursing home and was wondering if I need to inform Social Security of her living arrangements, down the road?

Thanks for any info.

Do you have durable power of attorney for your aunt? If so then you need to let the nursing home know she does receive Social Security as part of her income. The thing is right now Medicare should be paying for the nursing home care for either the first 100 days if your aunt has a medavantage Medicare plan. If she just has regular Medicare then Medicare will only pay for the first 20 days, the Medicaid kicks in. I would definitely talk with the business manager of the nursing home and find out how things are done.
If your aunt is going to be a permanent resident of the nursing home then you will need to stop all automatic payments coming out of her checking account, etc and revert to manual payments. I live in Washington and have Durable Power of Attorney over my Sister with nomination for guardianship.
I don't know if you have Durable Power of Attorney or not but you need to talk with the nursing home and find out how they handle things. I also suggest talking with an attorney who specializes in Eldercare Law, etc
I also want to wish you the very best. I know how confusing this road can be.