If you have a pension, you already know that most retirement advice ignores you.

The financial media is overwhelmingly focused on 401k and IRA accounts — defined contribution plans where you put money in, it grows, and you spend it down in retirement. Pensions are defined benefit plans. You do not own a pool of assets. You own a promise of future income, calculated by a formula you may or may not fully understand.

That difference makes pensions harder to model, and most retirement calculators either skip them entirely or handle them poorly.

Here is how the three main types of pensions work, how to think about each one, and how to build them into your retirement plan properly.

Type 1: The Formula-Based Pension

This is the classic pension. Your benefit is calculated as:

Years of service x benefit multiplier x salary basis

A typical formula might be: 1.5% x years of service x final salary.

So if you worked 25 years and your final salary was $90,000, your annual pension benefit would be:

1.5% x 25 x $90,000 = $33,750 per year, or $2,812 per month.

The "salary basis" varies by plan. Some use your final salary. Some use an average of your last three years. Some use an average of your highest three consecutive years. This matters because if you got a big raise in your final year, final salary is more favorable. If your salary has been flat, it may not matter.

The benefit multiplier also varies. Public sector pensions often use 1.5% to 2.5%. Some military pensions use 2.5% per year. Private sector plans tend to be lower, often 1% to 1.5%.

How Cola Affects Formula Pensions

Many pensions include a cost-of-living adjustment — a COLA — that increases your benefit each year after you retire. Some are fixed (1% per year), some are tied to inflation (up to a cap, often 2-3%), and some have no COLA at all.

A COLA sounds like a minor detail but it has enormous impact over a long retirement. A $2,812 monthly benefit with no COLA is worth less and less each year as inflation erodes its purchasing power. At 3% inflation over 20 years, it has lost roughly 45% of its real value.

The same benefit with a 2% annual COLA reaches $4,171 per month by year 20. That is a $1,359 per month difference, growing every year.

When modeling a pension, a COLA of 0 and a COLA of 2% produce dramatically different retirement plans. Know whether your pension has one.

Type 2: Cash Balance Pension

A cash balance plan works more like a 401k in some ways. Your employer contributes a percentage of your salary each year into a hypothetical account, and that account earns a guaranteed interest rate — often somewhere between 4% and 6% regardless of market performance.

The key difference from a 401k: you do not own the investments. You own a balance that the employer promises to maintain. The investment risk stays with the employer.

The key difference from a 401k: you do not own the investments. You own a balance that the employer promises to maintain. The investment risk stays with the employer. At retirement, you can usually take the lump sum or convert it to an annuity. For a full comparison of those two options, see the article on lump sum vs monthly pension payments.

Cash balance plans are more common in private sector companies and are increasingly replacing traditional formula-based pensions. They are more portable — if you leave the company, you can often roll the balance into an IRA.

To model a cash balance pension, you need:

Your current balance. Your employer's annual contribution rate as a percentage of salary. The guaranteed interest rate on the balance. And ideally, whether the contribution rate changes as your salary grows.

Type 3: Flat Monthly Benefit

Some pensions are even simpler. You retire and you get a fixed amount per month, starting at a specific age, until you die.

These are common in union agreements and some government plans. The benefit is negotiated, not formula-based. It might be $1,800 per month starting at age 62, full stop.

The modeling question here is just: does it have a COLA, and when does it start? If the flat benefit starts at 62 and you plan to retire at 58, you need to bridge four years without that income.

The Mistakes People Make With Pensions

Treating the pension as a replacement for savings, not a complement. A pension provides income, not a lump sum. If your pension covers your basic expenses, you still want investment assets for flexibility, healthcare costs, and unexpected expenses. The pension and the 401k serve different purposes. The article on how much extra to save if you have a pension works through exactly how to set the right savings target when pension income is part of the picture.

Ignoring the survivor benefit decision. Most pensions offer a choice at retirement: take the full benefit for yourself, or take a reduced benefit that continues paying to a surviving spouse. This is an irreversible decision with significant financial implications. If you choose the full benefit and die before your spouse, they get nothing from the pension. The right choice depends on your health, your spouse's health, and your other assets.

Not accounting for the pension's start date. A formula pension and a flat benefit pension typically start at retirement. But they might start at a different age than when you stop working. If you leave a job at 55 but the pension does not start until 65, you have a 10-year gap to fund from other sources.

Undervaluing the inflation risk. A pension with no COLA in a high-inflation environment loses real value fast. This is not hypothetical — retirees who retired in the 1970s with no-COLA pensions saw their purchasing power cut in half within a decade.

How To Build A Pension Into Your Retirement Plan

The right approach is to treat the pension as guaranteed income and your investment accounts as assets that generate additional income and provide flexibility.

For a formula or flat pension: calculate the monthly benefit at retirement, apply any COLA to project future years, and layer that income on top of the 4% withdrawal from your investment accounts.

For a cash balance pension: treat it like an additional investment account that grows at the guaranteed rate and converts to either a lump sum or annuity at retirement. If you take the lump sum, roll it into an IRA and model it alongside your other accounts.

The total retirement picture — pension income plus 401k withdrawals plus IRA withdrawals plus Social Security — gives you the complete monthly income you will have.

Most retirement calculators handle 401k and IRA reasonably well. Almost none handle all three pension types, the COLA, and the interaction between pension income and investment withdrawals in a single projection.

You can model cash balance pensions, formula-based pensions, and flat monthly benefits alongside your 401k, IRA, and HSA at NumberToRetire.com. The calculator handles COLA adjustments and shows how pension income combines with your investment withdrawals to give you a complete monthly income picture at retirement.