I have read that the "Gold Card" healthcare system covers all holders regardless of their "Socioeconomic" status. The local State hospital says that my wife has to pay half the cost of an operation because she is married to a "farang" and has my surname. Any comments?

If she has a "Gold Card", she is covered for all care that the system pays for. Who she is married to and what her surname is, has no relevance.

There are procedures that the system does not fully pay for, though. What is the surgery she needs?

In fact, there is no need for gold card anymore. It's just any Thai citizen. A national ID is only needed and all medical expenses shall be free..

BUT only at certain state hospitals. Not private!

If she has a "Gold Card", she is covered for all care that the system pays for. Who she is married to and what her surname is, has no relevance.

There are procedures that the system does not fully pay for, though. What is the surgery she needs?

Operation was for "Diverticulitis" and about ¼ of large intestine was removed.

In fact, there is no need for gold card anymore. It's just any Thai citizen. A national ID is only needed and all medical expenses shall be free..

BUT only at certain state hospitals. Not private!

She still must have registered in that hospital and the only one generally allowed is the address on her ID casrd as this is how they are funded. THe ID can be used to show elegibility if she is registered as the gold card is linked to this.

Nothing about that surgery that would have been ineligible for the national health system coverage AFAIK.