$169 per month. i was crying the other day when i signed up, so much stress lifted. >> reporter: but jessica stanford says it all went downhill from there. the state exchange had miss calculated her tax credits. and then there were more letters from the state exchange. she had started out with a plan for less than $200 a month and ended up with a plan she doesn't think she can afford. >> i got a letter telling me that they had made another mistake and that i wasn't going to be getting any tax credit at all. and so when i went online to look at the plan i bought, it went up to $390. it was a huge disappointment, and especially since i had, you know, my story had been shared by the president. >> reporter: and sanford isn't the only person in the state with miss calculated tax credits. it's actually more like 8,000 people. the exchange apologized saying we understand that this correct determination may have a large