I recently came upon this problem and was super confused on how to address an invitation to two doctors that are married but have different last names.
This is the information I found via The Knot
I hope this is helpful for you too!
If a wife and husband are both doctors,
the outer and inner envelopes should be addressed to:
"The Doctors Rosenthal."It's that simple!If they're married but have different last
names, list both names in alphabetical order on separate lines:"Dr. Rosenthal" followed by "Dr. Schwartz".If only one spouse is a doctor, list the
person with the professional name first:"Dr. Kate Randolph Mr. Brian Randolph"
or "Dr. Kate Randolph and Mr. Brian Randolph"(if it fits on one line).