i owe MD tax 17k, no longer a MD resident, in CA now. up to date with all my filing. owe for 13/14/15. filed CA and MD for 2016, and 2017 will only be CA. i made a payment agreement with irs already, but i dont have enough to make but a small payment to MD. if that doesnt cover my amount and if i cannot pay full amount, when do the collection becomes obsolete? after 36/72 months? what happened if my payment cannot cover that amount and i still owe after that? thank you

- up to date with all filings/ already have a payment agreement with IRS