We examined the impact of participation in certified organic production on farm earnings and net cash farm incomes of the US farm households. Using a nation-wide dataset and an unconditional quantile regression approach, we found a significant heterogeneous effect across different quantiles of farm earnings. Our results suggest that the effect of certified organic production is positive across the unconditional quantiles of net cash farm income but the effect is significantly larger for the farms with larger operations while smaller operations have low or non-significant effects.