Answer: If you are reporting modifier -22 (Unusual procedural services), you need to raise your fee to let them know how much more your think you deserve.
Because the claim will then go to manual review, you may just get what you ask for. There is no set reimbursement for this. Each payer determines what they will pay, and sometimes it will be less than 20 percent, sometimes more than 30 percent, and of course sometimes nothing at all.
The issue with labor management is that you cannot pinpoint the "usual" time it takes a woman to deliver, because some are easy and some are hard. Certainly if the physician spent 10 hours with the patient and was precluded from doing anything else because of her condition, you would qualify for modifier -22.
However, if the ob-gyn spent only four and a half hours, the outcome of higher reimbursement is a little less certain.