Inherited home that was recently sold

My Mom passed in September 2021.  She had lived in an apartment in Florida that she had purchased in 1998.  As per her will, I inherited this property.  I sold her apartment for 150k in April 2022.   So, about seven months after she passed. I have a primary residence in NY. 

 

I am requesting some clarification regarding reporting capital gains on this property .  Are capital gains derived based on the original 1998 purchase price - there were no improvements on her apartment since that time?  Or, are capital gains derived based on the value of the property at the time I inherited the property in September 2021. 

 

I read something recently that a stepped up basis process should be used.  If stepped up basis should be used - what is a way I can determine the cost basis of the apartment as of the date my Mom passed.

 

Thank you for any guidance on this and I admit maybe there are some elements of this that I need to still provide to help frame an answer to this.  I'm not seeking legal advice - just the best way to report the sale of this inherited property.