Hawaii Estate Planning 2026: The $5.49M Exemption, Portability, and What Honolulu Families Must Know

Hawaii imposes its own estate tax on estates above $5,490,000 — while the federal exemption is $15,000,000. A Honolulu couple with a home in Kāhala, rental properties, and investment accounts can easily have an estate that owes nothing federally but triggers hundreds of thousands of dollars in Hawaii estate tax. What makes Hawaii unique among the thirteen estate-tax states is this: Hawaii allows portability. A surviving spouse who files Form M-6 can preserve the deceased spouse's unused $5.49M exemption, protecting up to $10.98M combined — but only if they file the return, even when no tax is owed at the first death. Most Hawaii families never do. And unlike most state estate taxes, Hawaii has no state gift tax, making annual gifting a powerful and underused strategy for reducing taxable estates. This guide explains what Hawaii residents actually need to know in 2026.

How Hawaii estate tax works in 2026

Hawaii imposes its own estate tax under Hawaii Revised Statutes Chapter 236E, separate from the federal system. The tax applies to the Hawaii taxable estate — generally the gross estate (all property owned or controlled at death) minus allowable deductions — with an effective exemption of $5,490,000 per decedent.²

Above $5.49M, the tax is graduated, starting at 10% and rising to 20% on the largest estates. Hawaii has the highest maximum state estate tax rate in the country — higher than New York's 16%, Oregon's 16%, or Washington's 20% (Washington recently reduced to 20% on July 1, 2026). The rates are marginal: only the excess above each bracket threshold is taxed at the higher rate.

Source: HRS §236E-8. Rates apply to brackets above the $5.49M exemption. Actual liability computed on Form M-6. Values above are illustrative of the bracket structure; consult official Form M-6 instructions for precise tax computation. Marital deduction and charitable deduction reduce the Hawaii taxable estate under federal rules as incorporated by HRS §236E-3.

What Hawaii families actually owe — illustrative amounts

The table below shows approximate Hawaii estate tax for common estate sizes, assuming the gross estate passes entirely through the taxable estate at the second death (no marital deduction, no charitable deduction, no gifting). Actual liability depends on the full Form M-6 computation and allowable deductions.²

Hawaii portability — the planning advantage most families miss

Hawaii is one of the few states that allows portability of the estate tax exemption between spouses. When the first spouse dies, the surviving spouse can "port" the deceased spouse's unused Hawaii estate tax exemption — the DSUE (Deceased Spousal Unused Exclusion) — to their own estate.³

The mechanics: if Spouse 1 dies with a $3M estate (all of which passes to the surviving spouse under the marital deduction), Spouse 1 used $0 of their $5.49M Hawaii exemption. That full $5.49M DSUE transfers to Spouse 2. Spouse 2 now has $5.49M + $5.49M = $10.98M combined Hawaii exemption.

The portability trap: you must file Form M-6

Portability is not automatic. To elect it, the personal representative of the first decedent's estate must file Form M-6 (Hawaii Estate Tax Return) within 9 months of death — or apply for an extension on Form M-6A. This filing is required even if the first estate owes zero Hawaii estate tax.³

Most Hawaii families skip the Form M-6 filing when no tax is owed, believing there's no reason to file. The result: the first spouse's $5.49M exemption is permanently forfeited. At the second death, the surviving spouse's estate is taxed with only one $5.49M exemption instead of the full $10.98M — a mistake that can cost over $700,000 in avoidable Hawaii estate tax.

Portability vs. bypass trust: which is better for Hawaii families?

Hawaii families with significant estates have two primary tools for protecting both spouses' exemptions. Both work; the right choice depends on the estate size, asset composition, and planning goals.

Key insight for Hawaii families: Because Hawaii has the highest estate tax rate in the country (20% at the top) and the exemption is not inflation-indexed, large estates in Hawaii grow into higher tax brackets over time. A bypass trust captures that future appreciation outside the taxable estate permanently — which outperforms portability over a long time horizon as assets grow. For estates between $6M and $11M, portability alone (properly elected) may be sufficient. For $12M+ estates, a bypass trust typically delivers better long-term tax outcomes.

No Hawaii gift tax — the most underused planning tool

Hawaii has no state gift tax. Gifts of any size — to any recipient — reduce the Hawaii taxable estate permanently, with no Hawaii gift tax consequence. The only constraint is the federal gift tax system (annual exclusion of $19,000 per donee in 2026; federal lifetime exemption of $15M per person).⁴

For Hawaii families, this creates a powerful planning opportunity:

• Annual exclusion gifts ($19,000/donee in 2026) — each spouse can give $19,000 to each recipient per year. A couple with three adult children and three spouses = 6 donees × $38,000/year (joint gift) = $228,000/year removed from the Hawaii taxable estate at zero gift tax cost and zero federal exemption use. Over 10 years: $2.28M out of the estate.
• 529 superfunding — $95,000 per grandchild in a single contribution (5-year election), zero gift/Hawaii estate tax, removes value immediately from the taxable estate.
• Direct tuition and medical payments — unlimited, zero gift tax, zero estate inclusion. Grandparents paying tuition directly to a university: $50,000–$100,000/year removed with no tax consequence.
• Larger lifetime gifts — using federal exemption (up to $15M/person). Gifts today reduce the Hawaii taxable estate permanently. The recipient takes carryover basis (no step-up), but for estates generating substantial Hawaii estate tax, the estate tax savings often outweigh the capital gains trade-off.

California-to-Hawaii relocation: what changes for estate planning

California is the largest source of Hawaii in-migration for affluent retirees. If you're relocating from California to Hawaii for retirement, several estate planning considerations change materially.

Community property: you lose it when you move

California is a community property state. Hawaii is not — Hawaii is a common law state. When you establish domicile in Hawaii, new assets acquired after the move are common law property, not community property. California assets brought to Hawaii retain their character as community property (quasi-community property rules may apply under HRS §510-21), but this is a nuanced area requiring counsel.

Why this matters: community property assets receive a 100% step-up in basis at the first death under IRC §1014(b)(6) — both the deceased and surviving spouse's half get stepped up. Common law joint tenancy assets get only a 50% step-up. For California couples with low-basis appreciated assets, moving to Hawaii and re-titling assets incorrectly could forfeit the double step-up on the pre-move assets.

Hawaii estate tax exposure you didn't have in California

California has no state estate tax. Moving to Hawaii means your estate — previously exempt from state estate tax entirely — now faces Hawaii's estate tax starting at $5.49M with rates up to 20%. A California couple relocating to Honolulu with $10M in assets goes from zero state estate tax to a potential Hawaii estate tax liability of ~$560,000 if no planning steps are taken.

Hawaii Community Property Trust Act

Hawaii enacted the Hawaii Community Property Trust Act (HRS §§572D-1 et seq.), allowing married couples to opt certain assets into community property treatment within a Hawaii trust structure. This can preserve the double step-up in basis on assets contributed — potentially valuable for couples with appreciated securities or real estate who want step-up treatment without remaining in California. However, this is an evolving area with limited case law; work with Hawaii estate counsel before relying on this structure.

Strategies for Hawaii HNW families

1. File Form M-6 — even if no tax is owed

The single highest-impact action for most Hawaii married couples. File Form M-6 within 9 months of the first spouse's death to elect portability. Cost: $1,000–$3,000 in professional fees. Value: preservation of up to $5.49M in additional exemption at the second death, potentially worth $500,000–$1M+ in avoided Hawaii estate tax.

2. Annual gifting program

Use the $19,000 annual exclusion per donee per spouse ($38,000 joint per recipient in 2026). Target adult children, grandchildren, and their spouses. Hawaiian families with extended family networks can systematically remove significant wealth from the taxable estate each year with no Hawaii gift tax and no federal exemption cost.

3. SLAT for Hawaii-exposed assets

A Spousal Lifetime Access Trust removes assets from the donor spouse's estate while allowing indirect access through the beneficiary spouse. For a $15M+ Hawaii estate, a SLAT can shift $5M–$10M of assets out of the taxable estate entirely — saving up to $1.5M in Hawaii estate tax on those assets alone. SLAT assets and all future appreciation are permanently removed from both spouses' taxable estates at the second death.

4. GRAT for appreciated real estate and equity

Hawaii real estate often appreciates substantially. A Grantor Retained Annuity Trust (GRAT) transfers appreciation above the IRS §7520 hurdle rate (5.00% for June 2026) to heirs with zero gift tax. For a $2M Kailua rental property expected to appreciate at 8–10%, a 2-year GRAT can remove $150,000–$300,000 from the Hawaii taxable estate with zero exemption use. The GRAT does not trigger Hawaii gift tax.

5. Dynasty trust (South Dakota or Nevada)

For estates that will grow beyond $10.98M over time, a dynasty trust established in South Dakota or Nevada can shelter assets from Hawaii estate tax across multiple generations. The trust is established in a state without a rule against perpetuities, funded via SLAT or direct transfer, and governed by favorable trust law — while the family remains in Hawaii. Combined with the $15M federal GST exemption, a dynasty trust can shelter tens of millions from both Hawaii and federal estate tax for multiple generations.

6. ILIT for life insurance proceeds

Life insurance death benefits are included in the gross estate under IRC §2042 if the insured owns the policy. For a $12M Hawaii estate with a $3M life insurance policy, including the policy in the estate pushes the taxable estate to $15M — potentially adding $300,000–$500,000 in Hawaii estate tax. An Irrevocable Life Insurance Trust (ILIT) removes the policy from the taxable estate entirely; proceeds pass to the ILIT and then to heirs outside the Hawaii estate tax.

Hawaii estate planning case study: the Nakamura family

David and Jennifer Nakamura, both 68, live in Kāhala (Honolulu). Their estate:

• Primary residence: $4M
• Rental property (Kailua): $2.5M
• Investment portfolio: $3.5M
• IRAs and retirement accounts: $2M
• Life insurance (David owns policy): $1.5M
• Total gross estate: $13.5M

Federal estate tax: None. Both spouses' federal exemptions ($30M combined with portability) far exceed the $13.5M estate.

Hawaii estate tax without planning: At David's death, everything passes to Jennifer (marital deduction — zero HI tax at first death). No Form M-6 filed. Jennifer's estate grows to $15M over 10 years. At Jennifer's death: HI exemption $5.49M; taxable $9.51M; estimated HI tax: ~$1.4M+.

With portability only (Form M-6 filed at first death): Combined HI exemption $10.98M. Taxable $4.02M ($15M − $10.98M). Estimated HI tax: ~$500K. Saved vs. no planning: ~$900K.

With portability + ILIT: Life insurance ($1.5M) moved to ILIT, removed from gross estate. Taxable $2.52M. HI tax: ~$275K. Saved vs. no planning: ~$1.1M+.

With portability + ILIT + annual gifting ($76K/year to two children for 10 years = $760K): Estate at $14.24M; taxable $3.26M. HI tax: ~$385K. Plus the $760K in gifts are out of the estate and benefiting children directly. Net family benefit vs. no-planning scenario: over $1.5M.

With full planning (add SLAT for $3M): Another $3M removed from the taxable estate (and all future appreciation on that $3M). Taxable estate shrinks toward the combined exemption. HI tax approaches zero at that estate size, with Jennifer retaining indirect access to SLAT assets via beneficiary distributions.

7 common Hawaii estate planning mistakes

1. Not filing Form M-6 when no tax is owed. The most expensive mistake. Portability requires a timely return even if the first estate owes zero Hawaii estate tax. The 9-month deadline is strict; missing it permanently forfeits the deceased spouse's $5.49M exemption. A late election is possible in some cases (similar to the federal late portability rescue under Rev. Proc. 2022-32), but not guaranteed — plan for the deadline.
2. Assuming federal exemption protects you. The $15M federal exemption far exceeds most estates. But Hawaii's $5.49M threshold is far lower. Many families — and their non-specialist advisors — focus exclusively on federal planning and overlook the Hawaii exposure entirely.
3. Keeping life insurance in the taxable estate. Life insurance death benefits are included in the gross estate under IRC §2042 if the insured owns the policy. For a $10M estate with $2M in life insurance, the policy inflates the taxable estate over the Hawaii exemption, adding $200,000–$300,000 in avoidable Hawaii estate tax. An ILIT solves this completely.
4. No gifting program. Hawaii has no state gift tax, making annual gifting one of the most efficient tools available. Families that fail to execute a systematic gifting program leave a significant planning tool unused. Start early — the $19,000 annual exclusion per donee takes time to accumulate meaningful reductions, but 10–20 years of consistent gifting can eliminate Hawaii estate tax exposure entirely for moderate estates.
5. Relocating from California and re-titling community property to joint tenancy. California community property assets receive a 100% step-up in basis at the first death. Re-titling those assets as Hawaii joint tenancy after the move reduces the step-up to 50%. For low-basis appreciated assets, this can create significant capital gains tax exposure for heirs. Preserve the community property character of pre-move assets; work with Hawaii counsel on the quasi-community property rules.
6. Choosing portability over a bypass trust for a large, growing estate. Portability protects the DSUE amount as a fixed number. A bypass trust protects both the original amount and all future appreciation. For a $15M estate expected to grow significantly over the surviving spouse's lifetime, a bypass trust can save millions more in Hawaii estate tax than portability alone — at the cost of trust administration complexity.
7. Dynasty trust oversight. Hawaii limits the rule against perpetuities to 90 years for most trusts (HRS §525-2). For multi-generational planning, a dynasty trust is typically established in South Dakota or Nevada (both permit perpetual trusts) to avoid this limitation while naming Hawaii beneficiaries. Establishing a dynasty trust in Hawaii itself caps the trust's generational tax benefits after 90 years.