Effec­tive 2020 the allow­able con­tri­bu­tion for an indi­vid­ual HSA is $3,550 and for a fam­i­ly it is $7,100.

You can use them until you can’t – and then you must let them go – Com­muter Ben­e­fits 

In Infor­ma­tion Let­ter 2019-02, the IRS has con­firmed that unused trans­porta­tion ben­e­fits will be for­feit­ed when an employ­ee ter­mi­nates employ­ment.  It does not mat­ter how much or why – when the employ­ee is no longer active­ly employed, the remain­ing bal­ance in the account is forfeited.