What Is a CSA Number? The Two OPM Letters It Comes In
Updated September 28, 2026
Jay SasportasRetired fed, 33 years. Seven months in the same wait.Quick answer
Your CSA number (short for Civil Service Annuitant) is the claim number OPM assigns when it opens your retirement case. It comes in a welcome letter from OPM’s Boyers, PA operation, and a separate password letter from Macon, GA follows with the 8-digit passcode for your first Services Online login. The two can arrive in either order, and until the password letter shows up, nobody can log in.
Letters landing out of order? The free tracker turns them into one picture of where your case is.
Right after your case reaches OPM, the mail starts: a letter with a number on it, maybe an email before that, then another letter from a different city entirely.
None of it explains how the pieces fit. Mine didn’t either. Here’s what each piece is, the order they tend to arrive, and what actually gates what.
What is a CSA number?
It’s the claim number OPM assigns you as an annuitant. It’s also one of the three things you need for your first Services Online login.
One number, three costumes. OPM prints the same identifier in different formats on different pieces of paper:
- “CSA 9 XXXXXX 3” on one
- “A9XXXXXX3” on another
- “CSAN #A9XXXXXX3” on a third
Those are all the same number. The body is nine letters and numbers; only the presentation changes by document. If two OPM artifacts seem to show two different claim numbers, look again with that in mind before assuming a problem.
No CSA number yet? That’s information too. It means OPM hasn’t created your claim, so your case is still at the pre-OPM stage, with your agency or payroll. The how-long page covers that stretch.
What mail does OPM send first?
Two mailings, from two different OPM facilities, plus an optional email that can beat them both.
| The welcome letter | The password letter | |
|---|---|---|
| Comes from | OPM Retirement Operations, Boyers, PA | OPM, Macon, GA |
| What it looks like | A letter with a Retirement Services Reference Card punched into it | A pressure-seal mailer |
| What it carries | Your CSA number, plus the basics of what happens next | An 8-digit passcode for your first Services Online login |
| The deadline | None | The passcode expires in 30 days |
| Typical timing | Issued when OPM opens your case; arrives by mail days later | Usually a week or two after the welcome letter, sometimes before |
The welcome letter. The card is part of the letter itself; the printed instruction is “Slowly punch your card away from the letter.” One artifact, one date.
The letter’s process language covers the basics: interim payments start “as quickly as possible,” and your health and life coverage continue. Then this line, which is OPM telling you the second mailing exists:
You will be sent a password to access your retirement account through Services Online.
The welcome letter has a second job too: it’s effectively your “OPM has your package” receipt. In one documented case it was issued the day after OPM received the package, so its date sits close to when your case landed.
The welcome email, when it happens, can arrive before either letter. Retirees report it sometimes lands in spam.
The password letter carries the passcode you use once, together with your claim number, to link Services Online to a Login.gov account. Mine came about a week after the welcome letter, in a plain sealed mailer that looked like nothing.
Which letter arrives first?
Usually the welcome letter. Not reliably, and OPM says so itself:
You may have received this passcode letter before you received your welcome letter.
The two leave from different facilities and race each other in the mail. Getting the passcode first, or the welcome letter first, means nothing about your case.
One more sequence retirees report: interim pay landing before any of this mail does. A deposit with no paperwork yet is a known order of events. That deposit has its own page.
I have a CSA number but nothing more. Is that normal?
Yes. It’s the most common shape of the early mail: the welcome letter or email got to you, and the password letter is still in transit.
Nothing is wrong. The credential is in the mail, from a different building, and it hasn’t caught up yet.
Why can’t I log into Services Online yet?
Because first login needs three things at once:
- Your claim number (the welcome letter or email)
- The 8-digit passcode (the password letter)
- A Login.gov account
Until the password letter physically arrives, you can’t log in. The honest answer to “check your status in Services Online,” for a new digital filer, is “you can’t yet.” That early silence is a mail dependency, and a normal one.
The number on my letter won’t work in Services Online. What’s going on?
You’re in reported territory, not broken territory.
Multiple retirees report the CSA number on the welcome letter needed a trailing zero before Services Online would accept it. In one retelling, an OPM phone rep treated it as common knowledge (“just add a zero at the end, sheesh”).
Others report a lag between the letter and the system syncing up.
OPM hasn’t documented any of this anywhere, so I can’t tell you it’s a rule. I can tell you it’s a repeatedly reported experience. If activation fails on the exact number printed on your letter, you have company.
Once you’re in, the stage words Services Online shows you have their own decoder.
Track your own case free
Log each letter’s date as it lands. The free tracker turns three envelopes into one picture: when OPM opened your case, when the login gate cleared, and where you are against cases like yours.
Claim number in hand and ready to call? The Limbo Kit ($19) carries the written help request and what to ask once you’re through.
Can’t get OPM on the phone? Start with the phone line, decoded from real calls. It’s free.
Common questions
- What does CSA stand for?
- Civil Service Annuitant. The CSA number is the claim number OPM assigns you when it opens your retirement case, and OPM prints the same number in several formats (“CSA 9 XXXXXX 3”, “A9XXXXXX3”, “CSAN #A9XXXXXX3”).
- I got a passcode letter but no welcome letter. Is that a problem?
- No. OPM’s own FAQ says the passcode letter may arrive before the welcome letter. The two mailings come from different OPM facilities (Boyers, PA and Macon, GA) and don’t arrive in a guaranteed order.
- How long is the Services Online passcode good for?
- 30 days. It’s the one time-limited item in OPM’s early mail.
- I don’t have a CSA number yet. Can OPM tell me anything?
- A missing CSA number is itself the information: it generally means OPM hasn’t created your claim yet, and your case is still at the pre-OPM stage of the pipeline, with your agency or payroll.