Perhaps. Please read on.
If Kaiser confirms that this is a High Deductible Health Plan (an HDHP is more than just a high deductible policy) AND you were covered by this plan no later than December 1, 2018 (i.e., on December 1st or before), then you can, in 2019, create an HSA for 2018 and contribute to it, subject to the annual HSA contribution limit for 2018.
The limits for 2018 are $3,450 (plus $1,000 if you are 55 or older) for Self-only HDHP coverage or $6,900 (plus $1,000 if you are 55 or older) for Family HDHP coverage. Note that Self and Family are not a function of your filing status but of whether the HDHP policy covers only you, or you and at least one other person.
The contribution must be made before the due date of the return. Ensure that the HSA custodian knows that the HSA and the contribution are for 2018 (since their default will be to make it for 2019).
Enter this contribution for 2018 in the HSA interview on the screen lebeled "Let's enter [name]'s HSA contributions" (see screenshot below) on the SECOND line, the one that says "personally". The deduction will appear on line 25 on Schedule 1 (Form 1040).
