See what your HSA could be worth at retirement if you invest it instead of spending it on current medical bills.
This calculator projects your HSA balance if you invest your contributions rather than spending them on current medical expenses (paying out of pocket instead, and keeping receipts). The HSA grows tax-free, and qualified medical withdrawals — at any age, even decades later — are completely tax-free.
The "shoebox strategy": Many financial planners recommend paying current medical expenses out of pocket (even though you could use HSA funds) and saving the receipts. You can reimburse yourself from the HSA for those old expenses at any point in the future — even 20 years later — completely tax-free, while letting the HSA balance grow invested in the meantime.
The HSA is the only account with a "triple tax advantage": tax-deductible going in, tax-free growth, and tax-free withdrawal for medical expenses. A 401k is tax-deductible going in and tax-free growth, but withdrawals are taxed. A Roth IRA is taxed going in but tax-free growth and withdrawal. The HSA is strictly better than both for healthcare spending specifically.