What about the ones who IRMAA would apply to? If they didn't enroll in Part D when first eligible, would SS still hit them with the Part D IRMAA as well as Part B, or not until if/when they later enrolled?
You can't be charged with IRMAA or LEP until you actually enrolled. For IRMAA it's not like SSA/CMS is going to say "oh, you're eligible for Part D, but not enrolled in so much as a PDP, but we're going to collect the IRMAA from you anyway." And for LEP, they can't calculate it until you enroll to know how many months you're coverage gap is.