South Dakota Special Spousal Trusts: Maximizing the Step-Up in Basis for Married Couples

For an affluent married couple in Sioux Falls, Rapid City, or any separate-property state across the country who built a $10 million portfolio of low-basis technology stocks, commercial real estate, or a thriving family enterprise from scratch, the passing of the first spouse frequently triggers a painful tax trap. In standard separate-property jurisdictions, jointly held marital assets receive only a 50% step-up in cost basis when the first spouse dies-leaving the surviving spouse facing massive federal capital gains and 3.8% Net Investment Income Tax bills if they need to sell the business or rebalance the portfolio to fund retirement.

South Dakota Special Spousal Trusts solve this disparity by allowing married couples to 'opt in' to community property treatment for specific assets transferred to the trust under S.D. Codified Laws § 55-17-1 through S.D. Codified Laws § 55-17-14. By classifying designated holdings as 'South Dakota special spousal property,' which is statutorily defined as community property under S.D. Codified Laws § 55-17-5, the surviving spouse unlocks a 100% double step-up in tax basis to fair market value upon the first spouse's death under 26 U.S.C. § 1014(b)(6), potentially wiping out millions of dollars in built-in capital gains overnight.

Step-by-Step Process in South Dakota

Whether you reside in Minnehaha County, Pennington County, Brown County, or are an out-of-state couple utilizing a South Dakota corporate trustee regulated by the South Dakota Division of Banking, Pierre, establishing a compliant Special Spousal Trust requires strict adherence to statutory formalities.

Step 1: Select High-Appreciation, Low-Basis Assets for Transfer

Not every marital asset belongs inside a Special Spousal Trust. Couples work with their estate planning attorney and CPA to isolate assets with substantial unrealized long-term capital gains-such as concentrated equity positions, depreciated commercial properties, or closely held C-corporation and S-corporation shares-while keeping depreciated assets (which would suffer a 'step-down' in basis) and tax-deferred retirement accounts (IRAs and 401(k)s represent Income in Respect of a Decedent under 26 U.S.C. § 691) outside the special spousal property schedule.

Step 2: Appoint a Qualified South Dakota Trustee

Under S.D. Codified Laws § 55-17-1, at least one trustee of a South Dakota Special Spousal Trust must be a 'qualified person' meeting the nexus requirements of S.D. Codified Laws § 55-3-41 and S.D. Codified Laws § 55-3-39. Either or both spouses may serve as co-trustees alongside a South Dakota resident individual or a chartered trust company located in Sioux Falls, Rapid City, Aberdeen, or Pierre.

Step 3: Execute the Trust Instrument with Mandatory Statutory Capitalized Language

To be legally enforceable, S.D. Codified Laws § 55-17-1 requires that the trust instrument be signed by both spouses (it may be revocable or irrevocable). Crucially, S.D. Codified Laws § 55-17-2 mandates that the trust agreement prominently display specific warning language in capital letters at the beginning of the instrument advising both spouses of the consequences of classifying property as special spousal property and recommending independent legal counsel. Under S.D. Codified Laws § 55-17-14, full and fair financial disclosure between spouses ensures the agreement cannot later be challenged as unconscionable.

Step 4: Form South Dakota LLCs for Out-of-State Real Property and Retitle Assets

Because conflict-of-laws rules generally govern real estate according to the law of the state where the land is physically located (lex situs), couples owning commercial real estate outside South Dakota typically deed the real property into a Limited Liability Company registered with the South Dakota Secretary of State, Pierre via Form LLC-Articles, South Dakota, Secretary of State, Articles of Organization for a Domestic Limited Liability Company. The spouses then transfer their intangible LLC membership interests into the South Dakota Special Spousal Trust. Pursuant to S.D. Codified Laws § 55-17-8, the trustee must maintain strict accounting records distinguishing South Dakota special spousal property from any non-special spousal property held in the trust.

Step 5: Obtain Date-of-Death Valuations and Claim the 100% Step-Up at First Death

Upon the death of the first spouse, both the decedent's 50% share and the surviving spouse's 50% share of the South Dakota special spousal property receive a full fair-market-value basis adjustment under S.D. Codified Laws § 55-17-3, S.D. Codified Laws § 55-17-5, and 26 U.S.C. § 1014(b)(6)-provided at least half of the community property is includible in the deceased spouse's gross estate. The fiduciary and CPA document the stepped-up valuations using Form 706, Federal, IRS, United States Estate (and Generation-Skipping Transfer) Tax Return, Form 8971, Federal, IRS, Information Regarding Beneficiaries Acquiring Property from a Decedent, and subsequent capital transactions on Form 1041, Federal, IRS, U.S. Income Tax Return for Estates and Trusts.

Step 6: Administer Survivor and Bypass Sub-Trusts Under Sealed Court Protection

Following the first spouse's death, the trust can split seamlessly into a Survivor's Trust and a credit-shelter or dynasty Bypass Trust. If any judicial instruction or probate filing is ever needed in the Second Judicial Circuit Court, Minnehaha County, Sioux Falls, the Seventh Judicial Circuit Court, Pennington County, Rapid City, or the Fifth Judicial Circuit Court, Brown County, Aberdeen using Form UJS-232, South Dakota, Unified Judicial System, Case Filing Statement, the family's net worth remains permanently sealed under S.D. Codified Laws § 21-22-28 while honoring the settlors' intent as enforced in In re Sunray Holdings Trust, 841 N.W.2d 271 (SD Supreme Court 2013) and In re Florence Y. Wallbaum Revocable Living Trust Agreement, 813 N.W.2d 111 (SD Supreme Court 2012).

Strategic Asset Classes for a South Dakota Special Spousal Trust

The financial impact of achieving a 100% basis step-up versus a traditional 50% step-up under 26 U.S.C. § 1014(a) is most dramatic across three core wealth pillars.

Concentrated Stock Portfolios and Founders' Equities

Consider a married couple who purchased or founded a stock position with a cost basis of $500,000 that has grown to $8,500,000 ($8,000,000 in unrealized gain). In a standard joint tenancy or revocable living trust in a separate-property state, the death of the first spouse steps up only half the portfolio, leaving $4,000,000 in taxable capital gain if the surviving spouse diversifies the stock (costing roughly $952,000 in federal 20% capital gains and 3.8% NIIT taxes). Inside a South Dakota Special Spousal Trust, the entire basis resets to $8,500,000, allowing the surviving spouse to liquidate and diversify the entire portfolio the next day for $0 in federal capital gains tax.

Commercial Real Estate and Depreciated Rental Properties

Commercial buildings, agricultural ranchland, and multifamily apartment complexes carry a double tax burden when sold by a surviving spouse: capital gains on land appreciation plus a 25% depreciation recapture tax under 26 U.S.C. § 1250 on decades of prior write-offs. When commercial properties are held via an LLC inside a South Dakota Special Spousal Trust (and coupled with a partnership election under 26 U.S.C. § 754 where applicable), the 100% double step-up wipes out all accumulated depreciation recapture and allows the surviving spouse either to sell the building tax-free or to begin taking fresh, higher annual depreciation deductions from the stepped-up value.

Family-Owned Businesses and Privately Held Operating Companies

When a founder spouse passes away, the surviving spouse often wishes to sell the family business to a private equity buyer, key employees, or third-party acquirer. Without a Special Spousal Trust, selling a zero-basis family enterprise shortly after the founder's death forfeits nearly 12% of the total enterprise value to avoidable capital gains taxes on the survivor's half. Holding the company stock as South Dakota special spousal property under S.D. Codified Laws § 55-17-3 preserves the full sale proceeds for the family.

How Much Does it Cost in South Dakota?

Compared to the hundred-thousand-dollar or multi-million-dollar capital gains savings at the first spouse's death, the legal and fiduciary investment to create a South Dakota Special Spousal Trust is modest.

• Attorney Drafting & Tax Structuring Fees: Engaging a South Dakota estate planning lawyer from our directory to draft a customized Special Spousal Trust, prepare marital disclosure schedules under S.D. Codified Laws § 55-17-14, and coordinate dual independent counsel reviews typically costs $4,000 to $10,000.
• South Dakota Corporate Trustee Fees: If neither spouse resides in South Dakota, retaining a qualified South Dakota administrative trustee in Sioux Falls, Rapid City, or Pierre under S.D. Codified Laws § 55-17-1 generally costs $3,500 to $6,500 per year. (South Dakota resident couples can name a qualified South Dakota individual or family advisor at low or zero annual trustee fees).
• LLC Formation for Out-of-State Real Estate: Forming a South Dakota holding LLC with the South Dakota Secretary of State, Pierre costs a $150 state filing fee plus $500 to $1,500 in legal drafting per entity.
• Qualified Appraisal Costs at First Spouse's Death: Obtaining certified appraisals for commercial buildings or closely held family businesses to substantiate the 100% step-up on Form 706, Federal, IRS, United States Estate (and Generation-Skipping Transfer) Tax Return typically ranges from $2,000 to $7,500.

How Long Does the Process Take?

Planning ahead is critical because federal tax rules prohibit last-minute deathbed transfers from capturing a full step-up in basis.

• Trust Drafting, Disclosures, and Execution (3 to 6 Weeks): Completing financial disclosures between spouses, verifying statutory warning language under S.D. Codified Laws § 55-17-2, and executing the trust takes 3 to 6 weeks.
• Asset Retitling and LLC Funding (2 to 4 Weeks): Transferring brokerage accounts and recording deeds into underlying South Dakota LLCs takes an additional 2 to 4 weeks.
• Federal 1-Year Anti-Boomerang Rule (26 U.S.C. § 1014(e)): If appreciated property is gifted to a spouse within 1 year of that spouse's death and passes back to the original donor spouse, 26 U.S.C. § 1014(e) can deny the basis step-up. Funding your South Dakota Special Spousal Trust while both spouses are healthy and more than 1 year prior to death avoids this federal statutory hurdle.

Frequently Asked Questions (FAQ)