A citizen apply green cards for parents who live half time in USA

[tchang1216]

Hi, everyone,
My parents usually stay in USA for 4-6 months, and the rest of days stays in our home country. As I read uscis.gov, it has two ways to file I-130, One is to file as they live on our home country,and the other is filed as they stay in USA legally.
My question is that, since my parents spend half time in each place, I am not sure which way I should file for I-130, any advice or experience shared. Also, does anyone know the average time frame for my parents to get their greencard, if I apply for them next month?
Thanks in advance.

 

[ananga73]

Where do they typically spend more time? Do they file US taxes?

 

[Jackolantern]

If their plan is to keep spending 4-6 months per year in the US, they should just keep doing the same without a green card. It will be hard to maintain the green card for very long when spending less than 6 months per year in the US. In addition, having a green card will force them to file US taxes based on worldwide income.