Hi
Glad you are finding the site so helpful - after all that's why we started it.
In answer to your questions:
1. I'm not sure what state you are in and laws can vary from state to state, but in all the states I am familiar with you can only charge WC & NF for a 99203 on the initial visit (you can't use any other codes, 99204,99205, etc) and you can only bill a 99213 for followup visits. WC & NF don't accept the manipulation codes.
2. If the patient is being seen for two completely different problems - this would be unusual for a comp injury. If you are billing comp for one injury (even if it does involve two different areas of the body) you can only bill a comp case for one visit per day. So if you were going to treat two different areas, the only way to get reimbursed separately would be to treat the patient on different days. If you are treating the patient for two different areas and only one of the areas is relating to the comp then you can bill comp for the visit for the comp area, and the patient's regular insurance for the other area.
3. When you bill for the reeval after 6-8 weeks, you can only bill the 99214 code.
Good luck!
Michele