Should a subpanel have the bonding screw installed?

No. NEC 250.24(A)(5) and 250.142(B) require neutral and ground to remain separated downstream of the service disconnect. The bonding screw is only installed when the panel is service equipment, per 250.24(B).

How do I know if my panel is a subpanel or service equipment?

A subpanel is fed by four conductors from a breaker in another panel or disconnect. Service equipment receives the utility conductors directly. With an outside emergency disconnect ahead of it, the interior panel is treated as a subpanel with separated bars.

Grounds on One Side, Neutrals on the Other, No Bonding Screw. Is That Right?

A user asked the app about a Homeline panel with grounds on one bar, neutrals on the other, and no bonding screw installed. Whether that is correct depends entirely on one question: is this panel service equipment, or is it a subpanel fed from another panel? The hardware is identical; the code treatment is opposite.

Subpanel: separated is exactly right

Downstream of the service disconnect, neutral and ground must stay separate. 250.24(A)(5) prohibits grounding the neutral again on the load side of the service, and 250.142(B) forbids using the neutral for grounding equipment there. So in a subpanel the bonding screw stays in the parts bag, the neutral bar floats on its insulators, and the ground bar bolts to the can. The two bars on opposite sides of a Homeline panel are interchangeable; what matters is that the one carrying neutrals has no metallic connection to the enclosure. If neutral and ground were tied together in a subpanel, normal return current would flow on the equipment grounds, metal conduit, and even water pipe, which is the hazard the rule exists to prevent.

Service equipment: they must be bonded

At the service disconnect the story flips. 250.24(B) requires a main bonding jumper connecting the neutral to the enclosure, which in a Homeline is that green screw driven through the neutral bar into the can. Without it, a ground fault has no low impedance path back to the source and breakers cannot clear faults. So a main panel with the screw missing and the bars separated is a real defect, not a tidy install.

How to tell which you have

If the panel is fed by four wires, two hots, a neutral, and a ground, from a breaker in another panel, it is a subpanel: keep them separate. If the utility service conductors land in it, three wires with no equipment ground, it is service equipment: install the bonding screw and the grounding electrode conductor. Meter mains and outdoor emergency disconnects ahead of the panel often make the house panel a subpanel now under the 2020 and 2023 rules, which is why so many newer homes correctly show separated bars and no screw.

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