Do I need to file Form 8938 (understanding thresholds) if I lived and worked in the U.S. for 5 months in a tax year and then moved abroad?

It depends.  You must file if you are a US citizen or if you were considered a Resident Alien in 2023. Being considered a resident alien is determined by a multitude of factors such as;

• Residency Dates prior to 2023
• If you were here on a student visa and if you were exempted or not.

If you only arrived in the US in 2023 and stayed five months, you do not have a 8938 filing requirement.

Thanks!