LOTS of details in Federal retirement issues, example:

[elleng]

'To be vested (eligible to receive your retirement benefits from the Basic Benefit plan if you leave Federal service before retiring), you must have at least 5 years of creditable civilian service. Survivor and disability benefits are available after 18 months of civilian service. 5 after you are hired.'

McCabe won't leave without anything.

https://www.opm.gov/retirement-services/publications-forms/pamphlets/ri90-1.pdf

[Drahthaardogs]

1. He's fine.

The one thing he loses is keeping his insurance into retirement, which is really the last perk of federal employment.

His pension is safe

[wishstar]

3. Good point, he will lose ability to have Federal employee health care benefits forever

He will have to find private health insurance elsewhere and will only qualify for Medicare at age 65 when otherwise he would have been able to continue paying premiums to keep his Federal health care insurance plan

[wishstar]

2. Looks like he will be able to get his pension at age 60 if has 20 years service but not now any more

He would have been able to get an immediate retirement at age 50 with 20 years service but the firing 2 days before his 50th birthday deprives him of an immediate pension, but he will eventually get the pension at age 60.

Deferred Pension rules:
"If you leave Federal service before you meet the age and service requirements for an immediate retirement benefit, you may be eligible for deferred retirement benefits. You may receive benefits when you meet one of the following sets of age and service requirements:
Age: Years of service:
60 20


So by getting fired, he cannot begin drawing his pension now but will have to wait 10 years until age 60 to get his pension unless he decides to draw out his Federal retirement contributions. For most long term employees it is better to leave contributions in system and draw pension later.