I have read all the advantages of contracting with a TPA to perform COBRA administrative functions.
What are the disadvantages, if any?

The Plan Administrator still holds the liability for COBRA including not notifying a plan beneficiary of their COBRA rights.

That's the main disadvantage as casey points out. Just choose a reputable one, like COBRAServe or COBRA Source, and you shouldn't have anything to worry about. I would be a little weary if someone named Corey's COBRA Service was knocking on your door. There's not going to be much of a difference in cost between service providers unless you're looking for additional reporting requirements and other bells and whistles.

The disadvantages with using a TPA for COBRA administration, particularly one who really has their act together is complacency. Our complacency!

We have used a TPA (COBRAServ) for four years and, while it seemed expensive initially, we are more than satisfied. We have rationalized the cost by determining how many exceptions we did not make that would have turned around and bitten us on the behind.

When we resolve issues, questions or disagreements, we nearly always determine that the TPA was correct, and we were wrong or the error was on our part. (Our HRIS system frequently misses ee's with qualifying events. With 6,500 FTEs and a 25% turnover rate, we have a lot of them.)

Before we contracted with COBRAServ, we used a local TPA for two years - which was a disaster. I compare it to my trying to coach the Redskins. I know all the rules, but I'm not qualified to run the team.

Good Luck!

We use a company called EBS/Atlanta. They have been our administrator for over 5 years and has provided excellent service, plus have been a great resource for helping us prevent those few from dropping from the cracks by using electronic downloads from our system to their COBRA Management System. They assume full liability and keep us up-to- date on COBRA related issues. ALWAYS check out the references of any administrator. If they don't provide a detailed client list so you can check them out-run, don't walk to the nearest exit.