The TY2026 Constants, Mapped to Their Source Documents

Citing "the IRS" is not a citation. The 2026 retirement limits, income thresholds, and HSA figures come from three different documents with three different scopes — and knowing which is which is what separates a sourced constant from a rumor with a logo.

Every fall, secondary sources fill with 2026 numbers attributed vaguely to the IRS, and every spring a second wave arrives that many of those sources miss entirely. The primary documents are few, and each governs a specific set of constants. This piece maps the TY2026 figures in Worthune's facts registry to the documents that actually set them, because the map is the difference between updating constants and guessing at them.

The three documents

The spring document is the one that trips up maintenance calendars. HSA contribution limits and HDHP deductible and out-of-pocket thresholds are set by their own §223 revenue procedure on their own schedule — Rev. Proc. 2025-19 set the 2026 figures well before the October announcements. A rollover checklist that sweeps everything into October will find the HSA numbers already months old, and a writer who cites the fall documents for HSA figures is citing documents that do not contain them.

The retirement limits, from Notice 2025-67

The 401(k) elective deferral limit for 2026 is $24,500, with an $8,000 catch-up for age fifty and over. The overall §415(c) limit — employee plus employer contributions — is $72,000. The compensation cap under §401(a)(17) is $360,000. The IRA contribution limit is $7,500. Each of these lives in the registry as a year-scoped row citing the notice — some rows cite the combined IRS announcement pages that carry both fall documents — and the models that need them — employer-match, mega-backdoor Roth, backdoor Roth — read the rows rather than embedding the numbers.

The income-side figures, from the fall revenue procedure

The standard deduction for 2026 is $16,100 for single filers and $32,200 for married filing jointly. The top of the 10 percent bracket sits at $12,400 single and $24,800 joint. The long-term capital-gains 0 percent rate ends at $49,450 single and $98,900 joint, with the 15 percent rate running to $545,500 and $613,700 respectively. The estate tax basic exclusion is $15,000,000 — a statutory amount set by OBBBA and confirmed in the revenue procedure — and the gift-tax annual exclusion is $19,000. The capital-gains and estate-planning models consume the thresholds and exclusions through the registry's structured exports; the standard-deduction rows are cited by prose sitewide rather than consumed by a model.

The HSA figures, from the spring revenue procedure

For 2026: self-only HSA contribution limit $4,400, family $8,750. HDHP minimum deductibles $1,700 self-only and $3,400 family; out-of-pocket maximums $8,500 and $17,000. All six are calendar-year figures from the spring revenue procedure, and the registry's rows cite it by section.

• ✓Retirement limits — cite Notice 2025-67, not the revenue procedures.
• ✓Income thresholds, capital gains, estate and gift — cite Rev. Proc. 2025-32.
• ✓HSA and HDHP figures — cite Rev. Proc. 2025-19, published in the spring.
• ✓Statutory figures — cite the code section, and expect no annual movement.
• ✓When a secondary source cites none of these, treat its number as unverified.

Why the mapping is worth internalizing

The practical payoff is a maintenance calendar with the right number of entries. A team that knows the three documents watches for two events a year — the spring §223 revenue procedure and the fall pair — instead of rechecking everything continuously or, worse, once. And the citation payoff compounds: a published number that names its document can be verified in one click and challenged in one sentence, while a number attributed to "the IRS" can only be re-researched from scratch. Worthune's registry carries the sourcing on every row so that neither the engine nor the reader ever has to reconstruct it.