I am retired and became eligible for an HSA in 2016 with my high-deductible ACA insurance. After a lot of reading around, I found a suggestion here or on Bogleheads to look at Saturna, and they have been great for my needs. I am using the HSA for long-term tax-advantaged saving for health care expenses down the road, not to reimburse myself on a frequent basis for expenses incurred. I make my annual contribution in a lump sum and put it all into VGHCX (Vanguard Healthcare fund) and leave it alone.