CardsFan
Thinks s/he gets paid by the post
After careful consideration of my income-expenses flow diagram I (70+) see the following conceptual/practical boundaries:
Bucket A - Checking, bill-paying accounts (0-3 months)
Bucket B - MMFs, HYSA, dividends from taxable brokerage (4 months - 2 yrs)
Bucket C - SEP-IRA, Rollover-IRAs, 403(b) (3-10 yrs)
Bucket D - Roth-IRA accounts (10 yrs +)
Bucket A has two SSA and one pension monthly input. So the bucket does not need to pull much from the reservoir.
Bucket B will soon receive RMDs from Bucket C (in 2 years).
Bucket C is 60-65% equity funds. Some Roth conversion for two more years.
Bucket D is 100% equity.
I never thought about them as buckets, but your buckets above are almost identical to how we are set up.