I'm not even sure if they have a formal parthership agreement and even if they do I suspect that it is silent on cash balance funding. Some of the decision-making on expense allocation seems very ad hoc - some expenses are shared equally by each partner while others (especialy administrative overhead types of costs) are paid according to a formula (half fixed and half variable according to certain productivity measures).
Just by way of example for how arbitrary some of the decision-making seems, a rank-and-file employee (not a partner) left with a remaining balance < $5,000 in the plan. As they were looking to distribute to her, one of the HR admins noted that her account had a shortfall of about $500 and they were deciding on whether to invoice her for the shortfall. This didn't make any sense to me since I don't believe the rank-and-file employees contributed any of their own funds. That situation is what prompted me to start researching rules about taking distributions and funded status of the plan.
We are in the process of getting a lawyer to vet everything as part of her upcoming separation next year, since neither of us really trust that the officers and administration of the practice have a good grasp on things in general, not to mention the specifics of the cash balance plan.
Would it be worth reaching out directly to the actuary that performs the calculations on behalf of her plan to get a better understanding of where things stand?