Contribution limits
Annual contribution limit (combined across all your IRAs) is set yearly with cost-of-living adjustments. Catch-up contributions for those age 50+ add a fixed dollar amount. The contribution must come from earned income (wages, self-employment) or alimony from a pre-2019 divorce decree.
Traditional IRA deductibility
Contributions are fully deductible if neither you nor your spouse is covered by an employer retirement plan. If covered, the deduction phases out between income thresholds that depend on filing status. Even when not deductible, you may still contribute (a "nondeductible" contribution tracked on Form 8606).
Roth IRA contributions
Roth contributions are never deductible but qualified distributions are tax-free. The income limit phases out the contribution itself between thresholds (filing-status dependent). Above the upper threshold, no Roth contribution is allowed — unless you go through a "backdoor" by contributing to a nondeductible traditional IRA and converting.
Spousal IRA
A working spouse can fund an IRA for a non-working spouse. The combined contribution limit is doubled, but the contributions must come from the working spouse's earned income.
Rollovers
Direct rollovers (trustee-to-trustee) are unlimited. Indirect rollovers (you receive a check and redeposit) are limited to one per 12-month period across all your IRAs and the redeposit must occur within 60 days. Failed indirect rollovers become taxable distributions.
Companion forms and schedules
Most IRS publications are written to support one or more specific forms. The publication's first chapter typically lists the forms it covers, and the form instructions cross-reference the publication. Used together, the form instructions and the publication answer most line-by-line questions. When they conflict — which is rare but happens, usually after a mid-year legislative change — the form instructions generally win, because they are revised more frequently and reflect the most current IRS interpretation.
Annual updates worth tracking
Each year's edition of the publication updates inflation-adjusted dollar limits, references to the current-year forms, and any legislative changes from the prior year's tax bills. The "What's New" page at the front of each publication is the single highest-value page for an experienced reader; it flags exactly which paragraphs in the prior edition no longer apply. If you maintain a personal tax-planning workbook, building a discipline of re-reading just the "What's New" page each January catches almost every legislative change that affects a small-business return.