Dive into the holdings of that fund. I've discovered that sometimes a fund offered in a 401k for a low ER is actually holding other funds owned by the same company, each with their own ER. But the ERs of the things being held are not reported cumulatively, so it only looks cheap when in fact you are paying for both.
It was my understanding that the larger companies (TRP, FIDO, Vanguard) report TDF ER as the total, all-in, cumulative, ER.
From the Vanguard website, footnote on the 0.08% ER:
The acquired fund fees and expenses based on the fees and expenses of the underlying funds.From a Vanguard TDF prospectus:
This example assumes that the Fund provides a return of 5% each year
and that total annual fund operating expenses (of the Fund and its underlying
funds) remain as stated in the preceding table.Neither of those are as clearly stated as I would like. I have often wondered just how cleanly they can actually separate the costs.
Do you have supporting docs that say or imply it is additive for some mainstream company? It is a very important point you bring up. I have CITs in my 401k from BlackRock, and I have completely given up on actually getting documentation that allows my to not be worried about those things. ERs, actual holdings, and so on. Having that entire system propped up by greedy finance people does not instill confidence, but that's for another thread.