Nowadays lots of companies are offering HDHP (High deductible Health Plan). This plan comes with an option of health savings account or HSA. You can contribute up to 3500 (single) and 7000 (family) in the year 2019.
Lot of people dont know the advantage of Health savings account. Money you contribute in to HSA is pre tax deductible You can invest HSA money as well (Most of the HSA providers gives an option to invest it into mutual funds) Earnings from this investment are tax free You can take out the HSA money (similar to 401k or IRA) after 65 tax free
In short, You dont pay taxes when you invest the money (thats your pre tax dollars) You dont pay taxes on earnings as long as you dont withdraw it before 65 You dont pay taxes when you withdraw it after 65
This is much better than traditional IRA or 401k where you have to pay taxes when you withdraw the money. This is the best retirent option, as long as you use HSA money only for medical purpose or withdraw it after 65.
One should start investing in HSA in his/her earlier career.