While SWA doesn't have the A/B/C funds, they do offer a 401k match when we make up our contribution for the year in question upon returning to the company. They do the calculation based on what I would have worked had I been there. I'm not sure how the calculation is actually determined. I had heard that they used your previous 6 months of fulltime employment as a guide in determining how productive you were. SWA also gives a profit sharing contribution for the time you're gone. Again, this contribution is based upon what they think you would have earned.
I received a profit sharing letter a couple months ago that actually spelled it out pretty clearly.
Actual 2008 Eligible Compensation: 50k
2008 USERRA Deemed Compensation: 35k
My profit sharing contribution was based on 85k as opposed to just 50k.
Patch