Index Match function returns #NA

Looks like standard, run of the mill, floating point error. If you are unfamiliar with floating point errors, I have gathered several links here: https://www.excelforum.com/groups/ma...nd-errors.html You can see this by entering =(I2-A3) into any cell (and formatting as scientific, if needed).

I'm not sure what strategy you would like to use. The usual first suggestion is to use the ROUND() function to force the result to a suitable precision. I don't know what your expected precision is, but this might look like =...MATCH(ROUND(I2,6),... or nest the existing subtraction in I2 inside of a ROUND() function =ROUND(H2-G2,6). As described in the above discussions, there are other strategies as well. One way or another, the solution to this is to employ some strategy for dealing with floating point errors.