A recent decision from the District of Maryland underscores a recurring—but often underutilized—opportunity for policyholders: securing and enforcing additional insured coverage under another party’s liability policy. In Charter Oak Fire Insurance Co. v. Builders Premier Insurance Co., the court held that an equipment lessor qualified as an additional insured under the lessee’s policy and was entitled to a primary defense.

The decision is a useful reminder that additional insured coverage can fundamentally shift defense obligations and materially reduce a policyholder’s exposure. We build on the decision to highlight the practical steps policyholders should take to ensure that all potentially available insurance is identified and pursued.