I have a laminated IRR ID with an “INDEF” expiration date. Will I still be allowed on base?

You only need a federal ID to get on base

Yes, I get off and on Ft Bliss all the time with no hassle. It's a DD form 2.

Yes, you should still be able to get on base, Capt Brandon Charters -- hope to see you again sometime soon, brother!

Sure, if everything else good about it. Officers are Indefinite, as they have no ETS. Serve until you die or resign your commission.