90718
I don't do vacs but I went for the challenge at CMS and this is what you can do:
I didn't know which state, carrier, etc. but look up CMS, Medicare Coverage, general Info, Medicare Coverage Database, Overview, then on left side of screen click Search and the dialog box will ask you for the CPT code. I looked it up under Trailblazer, for example, and found this dated and effective 1/1/2007:
Tetanus (90703, 90714, 90718) - These injections are covered when given for an acute injury to a person who is incompletely immunized.
When a tetanus booster is given to a patient in the absence of an injury, the injection does not meet the coverage criteria for Medicare (even though it may be appropriate preventive treatment).
Article Number: I-80A-R2 (A39821)
I hope this example will point you in the right direction

KellyLR