You may be looking at an older set of instructions (there was also some back and forth earlier in the year with limit changes).
For 2018, the limit is $3,450 (plus an additional $1,000 for 55 or older) for a total possible of $4,450.
See page 3 instructions for Line 3 -
https://www.irs.gov/pub/irs-pdf/i8889.pdf
