Tax Constants 2027 (preview)

Name: PiggyMath 2027 Federal Tax Constants (Preview)
Creator: PiggyMath
Published: 2026-08-14
License: https://piggymath.com/terms/

Working calculators still use 2026. This page records only cited official 2027 amounts plus statutory rates. Unpublished inflation items stay blank.

Last updated: August 14, 2026

Preview, not a second calculator. As of 14 August 2026 the IRS has not published 2027 tax brackets or the standard deduction, and SSA has not posted the official 2027 Social Security wage base. PiggyMath will not invent those numbers. Use the 2026 SE tax calculator for live math. Sourced file: data/tax-constants-2027.json.

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Primary publications

Official 2027 amounts (already published)

HSA contribution limit: $4,500 self-only / $9,000 family
HDHP minimum deductible / OOP max: $1,750 / $8,700 self-only · $3,500 / $17,400 family
PTC required contribution (employer affordability): 10.22%
HHS 2026 FPL (governs 2027 coverage-year PTC): contiguous 1-person $15,960 + $5,680 per additional person

The live HSA calculator still runs 2026 limits ($4,400 / $8,750) so 2026 filing math does not silently change. When we dual-impl a 2027 runtime it will read these official values.

Statutory rates that do not wait on a 2027 Rev. Proc.

SE net-earnings factor: 92.35%
Social Security + Medicare combined: 12.4% + 2.9% = 15.3%
Additional Medicare: 0.9% above $200,000 / $250,000 MFJ / $125,000 MFS (not inflation-indexed)
Schedule SE filing floor: $400

Those are the figures the 2027 SE tax preview can state without guessing a wage base.

Not yet official — left blank on purpose

Social Security wage base: Not yet published
Standard deduction: Not yet published
Federal income-tax bracket dollar thresholds: Not yet published
401(k) / IRA / QBI inflation amounts and 2027 mileage rates: not yet published

The 2026 Trustees Report intermediate assumption lists a $190,200 2027 contribution and benefit base. That is a projection in Table V.C1, not the official CBB. We store it under projections so it cannot hydrate into a calculator.

Full constant table

Rendered from the 2027 JSON. Null values display as “Not yet published.” 2026 working list: Tax Constants 2026.

Key	Value	Status	Source	Effective	app.js path
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Frequently asked questions

Are 2027 IRS tax brackets published yet?

No. As of August 14, 2026 the IRS has not issued the annual inflation revenue procedure for tax year 2027 brackets or the standard deduction. PiggyMath calculators continue to use 2026 figures from Rev. Proc. 2025-32.

Is the 2027 Social Security wage base official?

No. The SSA contribution and benefit base page still lists 2026 ($184,500) as the latest official amount. The 2026 Trustees Report intermediate projection of $190,200 is a forecast, not the official CBB. SSA typically posts the official figure in mid-October with the COLA.

Which 2027 tax figures are official today?

IRS Rev. Proc. 2026-24 set 2027 HSA limits ($4,500 self-only / $9,000 family) and HDHP deductible/OOP amounts. Rev. Proc. 2026-26 set 2027 premium-tax-credit applicable percentages. HHS published 2026 poverty guidelines that govern 2027 coverage-year PTC. Self-employment tax rates (15.3% on 92.35% of profit) are statutory and do not wait on inflation tables.

How we dual-check calculator math: Methodology. Who publishes these tools: About.