Investing - Fun Retirement Tables

contents

(2026-05-30 revised) 

These three tables are important for retirement planning. They are subject to change and I might have entered them incorrectly, so when it comes to detailed planning or payment, check a more reliable source than me.

These are for 2023.

Social Security Taxable Fraction

The taxable fraction of your Social Security income is based on provisional income, PI = 1/2 of Social_Security_income + AGI (adjusted gross income - pensions, wages, interest, dividends, capital gains, etc.) + tax-exempt interest. If married, filing jointly, add the PI for both people.

If PI is $25,000-$34,000 for single people or $32,000-$44,000 for married and filing jointly, up to 50% of your Social Security will be taxable.

Above these intervals, up to 85% of your Social Security will be taxable.

The "up to" is resolved by filling out the tax forms. Apparently the algorithm is too complex to document any other way. (This reminds me of the HTML spec - HTML is defined by whatever the web browsers do.)

Medicare Surcharge - Income Related Monthly Adjustment Amount (IRMAA)

For Medicare part B and D -

If your income (specifically MAGI)  is over $97,000 ($194,000 if married and filing jointly) in any given year, two years later your Medicare premium will have a surcharge. This is recalculated annually.

MAGI (modified adjusted gross income) is your AGI (adjusted gross income)  modified by obscure things that I am not going to include here.

Table of Monthly Premium for Parts B+D

single		married		premium
$0 - $97,000		$0 - $194,000		$160.90
$97,000 - $123,000		$194,000 - $246,000		$230.80 + $12.20
$123,000 - $153,000		$246,000 - $306,000		$329.70 + $31.50
$153,000 - $183,000		$306,000 - $366,000		$428.60 + $50.70
$183,000 - $500,000		$366,000 - $750,000		$527.50 + $70.00
$500,000 -		$750,000 -		$560.50 + $76.40

Watch out for this when converting assets from a TIRA (traditional IRA) to a Roth IRA. These conversions add to your MAGI and can trigger IRMAA surcharges two years later.

IRA Required Minimum Distribution (RMD)

RMDs are required, currently starting at age 73. For each age, there is a fraction of your TIRA that you must withdraw, expressed as a life expectancy factor, Y. The amount to withdraw is the total value of the TIRA at the end of the prior year divided by Y. This applies to all pretax retirement accounts (TIRA, 401K, 403B, etc.).

You must withdraw total_value/Y and include that as part of your taxable income. You cannot transfer it to a Roth.

Table of Required Minimum Distributions

Age	Y		%		Age	Y		%		Age	Y		%
					90	12.2		8.2%		110	3.5		28.6%
					91	11.5		8.7%		111	3.4		29.5%
72	27.4		3.7%		92	10.8		9.3%		112	3.3		30.4%
73	26.5		3.8%		93	10.1		10.0%		113	3.1		32.3%
74	25.5		4.0%		94	9.5		10.6%		114	3.0		33.4%
75	24.6		4.1%		95	8.9		11.3%		115	2.9		34.5%
76	23.7		4.3%		96	8.4		12.0%		116	2.8		35.8%
77	22.9		4.4%		97	7.8		12.9%		117	2.7		37.1%
78	22.0		4.6%		98	7.3		13.7%		118	2.5		40.0%
79	21.1		4.8%		99	6.8		14.8%		119	2.3		43.5%
80	20.2		5.0%		100	6.4		15.7%		120+	2		50.0%
81	19.4		5.2%		101	6.0		16.7%
82	18.5		5.5%		102	5.6		17.9%
83	17.7		5.7%		103	5.2		19.3%
84	16.8		6.0%		104	4.9		20.5%
85	16.0		6.3%		105	4.6		21.8%
86	15.2		6.6%		106	4.3		23.3%
87	14.4		7.0%		107	4.1		24.4%
88	13.7		7.3%		108	3.9		25.7%
89	12.9		7.8%		109	3.7		27.1%

If you are more than 10 years older than your spouse and your spouse is the sole beneficiary on the TIRA then you get a new table. The table has your age  horizontally and your spouse's age vertically and each entry is (as in the table above) your expected years of life (the inverse of the fractional withdrawal). Too much to document here, TIAA has the complete table - https://www.tiaa.org/public/pdf/rmd-joint-life-expect-table.pdf . (Thanks Gwyn P. Williams.)

If you do not take out the full RMD, you will be taxed heavily on the undistributed part.