Can I make additional contributions to my 2018 HSA if I no longer am covered by a HDHP in 2019?

[nasec33q]

I retired at the end of May, 2018. I had a HDHP plan all year in 2018, although part of the year it was thru COBRA. I did not contribute the max while I was working and am trying to determine if I can make additional contributions for 2018 even though I am no longer in a HDHP for 2019 without triggering the excess contribution part. 

[MinhT · Accepted solution]

If you had a HDHP for all of 2018, you can contribute to your HSA up to the maximum allowed for tax year 2018, and you can do this before April 15, 2019.