Does anyone have any experience with or thoughts about coordinating a VEBA and a 401(h) account in a pension plan with respect to funding retiree welfare benefits?

Does the VEBA provide a reimbursement benefit (HRA), or a guaranteed medical (indemnity) benefit?

Generally, it the VEBA provides an HRA, the COB rules in both documents need to spell out the order of payments. If the VEBA is simply a self-funded health plan (of the employer, union, etc.) the COB rules in the 401(a) plan should stipulate that those reimbursement amounts are payable only after proceeds from all health plans or health insurance policies.