What is established and what remains unreviewed
This website has not received independent professional tax certification. Moss Ladder owns and operates the site; an operator byline does not represent tax expertise. Educational wording is checked against linked IRS references, while automated unit and browser tests check selected engineering behavior.
Tests include basis conservation, taxable plus tax-free conversion totals, other distributions, contribution timing, invalid input, unsupported-case suppression and interaction across tools. A passing test demonstrates the behavior of the tested cases, not the completeness of a taxpayer's facts or the correctness of every possible legal interpretation.
Tax years and transactions covered
The 2025 standard Part I/II allocation references published Form 8606 and its instructions. The 2026 worksheet uses the 2025 structure as a planning estimate. The IRS instruction page checked for this update still describes 2025; the site does not claim that final 2026 filing behavior has been verified.
Roth IRA withdrawal ordering, inherited IRA treatment, QCDs, HSA funding distributions, certain repayments/disasters, SIMPLE transactions inside the initial two years and complex deduction/basis adjustments are outside the ordinary model. The warning controls identify review-only scenarios rather than solve them.
How to check a result or report a problem
Compare the tax year, owner, documented basis and annual transactions with the official form and your own records. A calculation can be arithmetically consistent but based on an incorrect year-end value or an unsupported transaction. Reconcile the data before drawing a conclusion.
Send suspected errors to contact@mossladder.com with the page URL, source, steps and invented sample amounts. Do not email tax returns or identifying account information. See the editorial policy for correction handling. Individual eligibility, reporting and transaction decisions need qualified review.