Thanks, Jason. The info link on the carlotta-nais-phalerata-vittata page is very helpful. I've added an additional photo of this moth to show its collar spots. Does this help narrow the ID any further, perhaps to A. phalerata?

I would say that additional photo does indeed help. Being that your specimen is a male, the two spots on the patagium would fit well with typical phalerata and vittata. Males of carlotta and nais typically do not have the patagium spots (though they can), plus nais shouldn't be in your area (coastal plain). The wing shape of yours also fits well with typical phalerata and vittata, and given that vittata is primarily a southeastern species, I would feel fairly comfortable IDing your specimen as species phalerata based on the sum of characteristics, with the usual caveat that genitalic dissection is the only sure fire way to be certain of ID.