Substantial presence indicates I may need to list myself as a resident of California instead of Georgia. Not sure how I should list myself.

[yoshieb]

I live in an apartment paid for by my company while I do contract work out in California. I've spent over half of the year here, and I'm unsure if that makes me considered a resident of the state by default due to the 183 days test.

[jerry2000]

California does not have a fixed "substantial presence" number of days, it depends on the specific circumstances. The guidelines for determining residency are in the California Franchise Tax Board publication 1031, which you can find at this link:
https://www.ftb.ca.gov/forms/2016/16_1031.pdf