US Dept. of Health & Human Services

https://www.hhs.gov/

Centers for Medicare and Medicaid

https://www.cms.gov/

CAQH

https://www.caqh.org/

Blue Cross Blue Shield

https://www.bcbs.com/

Aetna

https://www.aetna.com/

Humana

https://www.humana.com/

United Health Care

https://www.uhc.com/

USPS Zip Code Locator

https://tools.usps.com/go/POLocatorAction!input.action