I retired early (age 47) from the Federal government with a FERS deferred pension (18 years of service) that I'll start in about 8 more years. My basic plan is as follows:

...

- Start drawing pension at MRA (56.4 years)

So your pension would be reduced 28%, right? (62 - 56.4 =5.6 * 5% = 28%)? If inflation averages 3% in the 9.4 years between your quit date and drawing the reduced pension, that reduces the value ~25% [1/ (1.03^9.4)]. So your pension will be worth 18% * 72% (28% reduction) * 75% = ~9.8% of your salary in inflation adjusted terms.

Where as someone in the same position who stayed to MRA+30 would get 28.4%, plus the SS supplement until 62 plus retiree health benefits plus you get to count unused sick leave towards years of service (as well as the salary being higher for any grade and step increases). They really make you give up a big part of your pay package to retire early. If DoubleDown's 18 year career ended at 62, I toss out a sample salary figure of 80k, and you estimate a 5% annuity factor (higher than 4% since there is guaranteed to be no residual value), I'd estimate the NPV at his retirement date to be $288k plus whatever value you want to put on retiree health benefits. In DoubleDown's actual scenario using my made up 80k salary figure, [(80k * 9.8%) / 5%] = $156.8k is an estimate of the FUTURE value 9.4 years after his retirement date. So if you assume 4% REAL investment returns, the value at the time of retirement would be [156,800 / (1.04^9.4)] = ~$108.5k. Pension for a 47 yo with 18 years of service is worth $108k. Pension for a 62 yo with 18 years of service is worth $288k plus whatever value you put on health benefits (or do you have to have 30 years for health benefits?).

The value of retirement benefits becomes exponentially larger as you get closer to MRA. In my salary range, I figure by the time I'm 10 years out from MRA, the incremental retirement benefits alone are worth at least as much as being paid an extra $30k per year (i.e. at 10 years before MRA, calculate the FV of pension if staying til MRA, then calculate the NPV of a deferred pension for retiring 10 years early- you would have to invest >30k per year for 10 years to make up the difference). If you compare retiring at MRA vs one year before MRA, the amount you get paid for that last year is well into 6 figures just in retirement benefits (not counting salary). I'm not trying to persuade anyone into working until MRA, just trying to quantify what you have to give up.

My agency is probably unusual in that they allow us to go part time. You can still retire at MRA+30 with an unreduced pension. Working half time for a year just counts as half a year for the pension calculation, but still counts as a full year towards the MRA+30. So my tentative plan is to go part time when I get closer to FI. I still expect to be FI by my early 40s, but I think I'll still want to work part time, and I'm not someone who would agree with the statement "If you're FI and want to work part time, it doesn't matter whether it pays $10k/yr or $50k". But if 45 yo me decides he wants to quit and travel full time or whatever else, he'll still have that option. Again, not trying to persuade anybody to work to MRA, just saying what MY plan is.