I have an M.D., but never practiced medicine. I have been tutoring junior high- and high school kids in math, science, and some English for several years with various franchises and small companies, while following my wife here and there while she is pursuing higher medical education. Am I “behind in the game”? How do I increase my “stock”/chances? (I’m thinking of teaching anatomy and physiology to nursing and allied health students. I considered going back to school to get certified for teaching math and/or science on the secondary level, but I can’t afford it.)
I got my M.D. six years ago.
Translate Post: 
Keep on doing the job you are doing, and try to spend less money and when you have collocted the money you will be able to continue colloge, and since you are teaching ate high school it would look good on your qualification.
Go talk to someone at one of the nearby community colleges. They usually require only a masters degree to teach and often will even accept only a bachelor’s if you have field experience.
Sorry, but your MD is not enough to qualify you to be a teacher. You need teacher training as well as student teaching (interning as a teacher). You may certainly have enough science and math to qualify you in those subject areas, but you also need to know and understand the fundamentals of teaching, including various methodologies, learning styles and teaching techniques to address those styles, knowledge of the needs of special education students, testing and measurement, lesson planning, and ways to maintain good discipline. If you cannot afford to go back to school to learn these skills, then look for a job other than teaching. Good luck.
Chow!!