In 2016 I had a high deductible plan through my employer and made pre-tax contributions to an HSA. I did not meet the HSA contribution limit for 2016 and have remaining medical bills from 2016 that I have not yet paid. For 2017 I switched to a PPO plan with an FSA and now am making pre-tax contributions to my FSA for 2017. Can I make post-tax contributions to my HSA (until the April tax deadline) to pay for the medical bills from 2016 and claim those contributions as personal contributions to an HSA on my 2016 taxes?
