This research uses plausibly exogenous variation in ambient fine particulate matter (PM2.5) driven by wildfires to causally estimate effects on health insurance enrollment. I use estimates of wildfire-PM produced by Childs et al. (2022) and combine this with self-reported enrollment status from the American Community Survey (ACS). Exploiting within-area variation over time, I find that increases in wildfire-PM exposure increase the probability of health insurance enrollment, and these effects are completely driven by Medicaid. A one standard deviation increase in average annual wildfire-PM increases the probability of Medicaid enrollment in the following year by about 1 percentage point. The results are robust to alternative specifications and reveal that Medicaid enrollment can be a response to air pollution exposure among those eligible. I also present suggestive evidence that the mechanism driving this effect is self-enrollment due to a perceived increase in the expected value of health insurance which may be mitigating the health damages of wildfire-PM exposure in low-income populations.