pips&peeps
There is no "I" in Ameraucana
They do not test for Marek's as part of the NPIP program. Birds can be exposed without contracting the virus if they have an immunity so the only sure way to confirm Marek's is through necropsy. Vaccinated birds would test positive if they tested for it.
This would only be true if the bird actually had mareks. The current vaccine is not actually the chicken mareks virus, but the turkey mareks virus and is close enough that it gives the bird immunity. The only way to test for mareks is through necropsy.