Is playing multiple money cards multiple actions in Monopoly Deal?
Adding three money cards to your bank counts as all three of your actions.
The rules describe step 2 of the turn as:

Play up to 3 cards
... Play 3 cards in any combination of the following: ...
A. Put Money/Action cards into your own bank ...
B.Put down properties into your own collection ...
C. Play action cards into the center

Putting down three money cards would count as playing three cards, all three of which fall under category &quot;A&quot; above.