Badge of Infamy - Lester Del Rey - Bog

In the future, powerful unions called lobbies control much of society. One of the most powerful lobbies is the medical lobby, which following a pandemic that spread across earth, has required all medicine from being practiced only by authorized lobby members and only in approved lobby facilities. Daniel Feldman was once a doctor but has now become a pariah due to his breach of these rules. Trying to escape the shame he travels to Mars, where he discovers a disaster threatening billions of lives.