Using all available data with xtreg

Hello-

I am using xtreg to conduct an analysis of executive function skills and academic achievement with fixed effects. I have repeated measures from 6 time points. I am writing this post to see if there is a way for Stata to use all available data and not delete cases with missing data. Some cases only have two waves of data, but I would like to keep these cases.

Thanks in advance for any feedback.

Best,
Michael