This may or may not be a correct answer, depending on the sample space you have used. (Remember: an event is a subset of the sample space, so you should always construct a sample space before constructing an event.) If your sample space was

S = {covered by employer's plan, covered by own plan, covered by spouse's plan, not covered},

then your answer is correct. If your sample space was

S = {covered by an individual plan, not covered by an individual plan},

then your answer is wrong.