Health Reimb. Accts - Cap On Lifetime Accrual?

[Christine Roberts]

Under HRAs the employer can impose a cap on carry-overs from one plan year to the next -e.g., max carry over is 50% of the annual reimbursement budget.

Is it permissible to cap lifetime accruals, as well? E.g., maximum accrual under the plan limited to $50,000.