Best way to bring girlfriend and biological son to US?

I’m a US citizen, unfortunately I haven’t lived there for 5 years prior to my son’s birth, but I do work for a US company and have lived for about 2 years total in US. My son is 3 and was born in the Philippines to my girlfriend. I know that I can do a K1 Visa, but does anyone know how that works if the son is biological? I would like to give him US citizenship but it seems like I don’t satisfy the 5 year requirement. Any thoughts?

The K-1 visa is probably the quickest route to bring your girlfriend to the United States. It will take between 5 to 10 months for a K-1 fiancé visa from the date of filing to the date of entry to the United States. You can visit the website of DYgreencard Inc. They are the immigration services providers and you should visit their website to get more information related to K1 visas.