Thistlebourne

Retirematics is a one-person site. The arithmetic, the data files, the explanations and this page are all the work of the same person, who publishes under the name Thistlebourne.

Who is behind this

Thistlebourne is a pen name and nothing more — not a firm, not a team, not a placeholder for someone else. Writing under one makes the limits easier to state plainly: nobody behind this site holds a licence. There is no financial adviser, actuary, CPA or attorney here, and no page on the site implies that there is. I am an independent developer and publisher, and that is the whole of it.

The skill this site actually requires

Deciding when to claim Social Security, whether to start a 72(t) series, or what to do with a pension offer are judgments about your circumstances. I am not in a position to make any of them, and nothing here substitutes for a licensed professional, the Social Security Administration or the IRS.

What these pages do require is narrower and more mechanical: reading a statute, a regulation, an IRS notice or an actuarial table closely enough to turn it into code, then proving the code reproduces the agency's own worked examples. That is a documentary and programming skill rather than a professional one — and it is the only thing I am claiming to bring here.

How a number gets onto this site

1. It is read out of a primary document — the Code of Federal Regulations, an IRS notice or revenue ruling, an SSA page, a published actuarial table. Second-hand summaries do not qualify as a source.
2. A second, independent reading of the same document has to produce the same figure. Where the two disagree, or where a statute and an agency's own booklet disagree, both readings are recorded rather than quietly reconciled.
3. A third pass tries to break the result: recomputing the agency's published examples by hand and comparing them with the calculator line by line, then pushing implausible inputs at it to see what it does.
4. Confirmed figures become automated tests. The site cannot be built while any of them fails.

The visible consequences are on the pages themselves: each factual statement carries the document it came from and the date it was last checked, the methodology page sets out every rule the engine applies, and the corrections log records errors that were found — including ones that were live on the site. I use language models to help read and cross-check the documents. They settle nothing: every figure and every sentence that reaches the site has been checked back against its source document by me.

What this site deliberately leaves out

A calculator that quietly ignores a rule is worse than one that says it does. The Social Security tools do not model survivor benefits, family maximums, the special minimum PIA or Medicare premiums. The drawdown projection does not model state income tax or itemized deductions. The RMD tools do not model inherited accounts, annuity contracts or the year-of-death minimum. Every calculator carries its own section saying what it leaves out, directly under its results, and the methodology page sets the same exclusions out tool by tool.

No professional review, and how you would know

No financial adviser, actuary, CPA or attorney has reviewed this site. If that changes, this page will name the reviewer, their credential, exactly what they reviewed and when, and it will say plainly what fell outside that scope. Until such a line appears here, read every figure as a careful reading of the published rules — which is what it is — and not as advice.

Telling me I am wrong

Email support@retirematics.com. The reports I can act on quickest name the page, the figure you expected instead, and the official document it comes from; I check that document. When the report is right, the data file is corrected, a test is added so the figure cannot drift back, and the change is written up on the corrections page with its date.