1-step TB test = 2 appointments
You will attend one appointment to have the TB skin test given and a second appointment 48–72 hours later to have the result read.
2-step TB test = 4 appointments
A 2-step TB test involves two separate TB skin tests. Each test requires an appointment to have the test given and another appointment 48–72 hours later to have it read, for a total of 4 appointments.