How long my Netsuite instance doesn’t have the account field for bills or invoices?

When you say account, do you mean Client/Company you are invoicing? If so, You'll want to use the Customer field on your screenshot. If you mean account from your chart of accounts, that will be automatically determined by the items you include in your invoice.

Thanks @Tim_Pedersen! Interestingly, on the Bills page, I have an account that has the Account field on the top level but on another it doesn’t exist. For the life of me, I can’t figure out where the config lives that enables this. Curious if you have any insight.

Which definition of "Account" are referring to? 1. Chart of Account 2. Custom record? The layout of your transactions can be set based on the role you are in. If you are saying that some invoices pull up differently than others, than I would say that you have different transaction form layouts involved. Other transactions will allow you to choose the account across the entire transaction - regardless of the line item. For example, and Inventory Adjustment transaction will specific the GL Line

Chart of Accounts. I see, so this might be a roles issue

I wasn't aware that an invoice transaction could force a certain Chart of Account for the WHOLE transaction. Some transactions can, but invoices??

If you take a look at the two screenshots that I shared in my first comment, I think I’m comparing the same page?

You have 3 screenshots total - 1 of an invoice, and 2 others of a Bill record. Bills can stipulate a single account (you are paying someone else from an account). Invoices cannot stipulate a single account for the entire transaction. Since someone else is paying you, you have the flexibility to designate the involved accounts based on the items listed on the invoice. Each item allows for a separate Income account for example.

also one of the vendor bills in the side by side screen shot is a custom form, which just may not have 'account' set to show on the form.

Maybe you only have one Accounts Receivable account in your COA.