Capital gains tax...

[Mark E]

I have an issue coming up were my parents are selling there investment home of 6 years and want to re-invest in another state. However, will they avoid paying capital gains if they buy a property acouple of months after the sale of there current investment? Or are there guidelines like the home has to cost more than the current investment to avoid the gains ex. current home worth 400,000. And investment home they want to purchase is 160,000. Will they still avoid the gains or will they have to purchase a home worth the same or more than 400,000? Thanks!