Do i have to have the hsa set up before jan 1 to use the benefits of hsa for 2018?

[BMcCalpin · Accepted solution]

No. There are two requirements:

1. You have HDHP coverage

2. You have set up the HSA at some point after you got HDHP coverage. It does not have to be last year in order to get benefits for tax year 2018.

Note that the annual limit for HSA contributions is dependent on how many months you are under the HDHP, not how many months you have the HSA. However, if you are under the HDHP on December 1, 2018, then you will be able to use the full annual HSA contribution limit, no matter how few months you had HDHP coverage in 2018 (it's called the "last-month rule").

[dmertz]

Just be aware that you can only use the HSA to cover medical expenses incurred after the date on which you established the HSA.  Generally, the date on which you established the HSA is the date on which money is first deposited into the HSA.