L3 Ch4 L1 closed the Social Security claiming workflow. L3 Ch4 L2 — the Medicare IRMAA two-year lookback and coordinated income smoothing workflow — handles the related government-benefit decision that compounds across every other planning workflow the practice runs. Project AGI two years out (2026 IRMAA tier determined by 2024 AGI; 2027 IRMAA tier by 2025 AGI), identify the income-bracket cliff, design the income smoothing across Roth conversion timing, capital gain harvesting, deferred-comp election under IRC §409A, QCD usage under §408(d)(8), HSA contribution above-the-line reduction, and any other AGI-management lever to avoid the cliff. The deliverable: one integrated memo per household showing claim/convert/RMD/harvest/IRMAA together — the multi-workflow capstone the L3 Ch4 sequence delivers. The household sees not a tax memo, a Roth memo, an SS memo, an estate memo separately, but a unified retirement-income picture across the four-year planning horizon.

The IRMAA Cliff Mechanics

Medicare's Income-Related Monthly Adjustment Amount (IRMAA) is a premium surcharge tied to AGI two years prior. The CMS publishes annual tier thresholds in late Q4 of the prior year for the following plan year. 2026 IRMAA thresholds (illustrative; verify against current CMS): MFJ Tier 0 base premium AGI ≤ $206,000; Tier 1 $206,001-$258,000 (+$70/month Part B + $13/month Part D ≈ $83/month × 12 = ~$1,000/person/year); Tier 2 $258,001-$322,000 (~$175/month Part B + $33 Part D ≈ ~$2,500/person/year); Tier 3 $322,001-$386,000 (~$280/month + $54 ≈ ~$4,000/year); Tier 4 $386,001-$750,000 (~$385/month + $74 ≈ ~$5,500/year); Tier 5 above $750,000 (~$420/month + $82 ≈ ~$6,000/year).

The "cliff" feature: tier-thresholds are step-functions, not graduated. AGI of $322,001 vs $322,000 — one dollar over — pays full Tier 3 premium for the entire year. For both spouses on Medicare (typical retired couple), the differential is doubled per couple. The IRMAA workflow's central optimization is to avoid crossing tier-thresholds when possible — typically by sizing income-generating events ($5-10K below the cap to leave margin).

The Two-Year Lookback Mechanic

The 2026 IRMAA tier determination uses 2024 AGI (reported on the 2024 1040). Decisions in 2024 affect 2026 Medicare premiums. The 2027 IRMAA uses 2025 AGI. The 2028 IRMAA uses 2026 AGI. Planning horizon is therefore always two years forward. The L3 Ch4 L2 workflow projects AGI two years out using the household's other planning workflow inputs: Roth conversion schedule (L3 Ch2 L2), RMD calendar (L3 Ch3 L1), Social Security claiming schedule (L3 Ch4 L1), capital gain realization plans, deferred-comp distributions, HSA contributions, business income (if applicable).

The 2-year lag creates planning opportunities. A client in 2026 considering a 2026 Roth conversion of $74K knows the 2026 AGI will determine 2028 IRMAA — there is time to plan the conversion size against the projected 2028 IRMAA tier. If the conversion would cross the cap, smaller conversion is recommended. If margin remains, conversion is well-positioned.

Life-Event IRMAA Appeal

If a major life-event materially changes income (retirement, death of spouse, divorce, work stoppage, loss of pension/income), the client can file Form SSA-44 (Medicare Income-Related Monthly Adjustment Amount — Life-Changing Event) to request the IRMAA tier be recalculated based on current income rather than two-year lookback. The L3 Ch4 L2 workflow's regulatory checkpoint flags life-event candidates for appeal. The CMS reviews and may grant a current-year tier reduction. The L3 Ch5 estate workflow's life-event triggers feed this analysis.

The Income-Smoothing Toolbox

Multi-lever income-smoothing requires deploying multiple workflows in coordination. The L3 Ch4 L2 memo names each lever.

Roth Conversion Timing

Per L3 Ch2 L2, conversion sizes target federal bracket fill + IRMAA tier margin. The L3 Ch4 L2 memo coordinates across years: aggressive conversion in low-AGI years (before SS claim, post-business-sale); tapered conversion in higher-AGI years; defer conversion in years where the tier-cliff is unavoidable.

Capital Gain Harvesting

Long-term capital gains taxed at 0%, 15%, or 20% federal depending on bracket. Strategic capital-gain harvesting in low-income years (e.g., the pre-SS-claim window) realizes gains at the 0% bracket up to the top of the 0% threshold (~$96,700 MFJ for 2026 LTCG 0% bracket). Tax-loss harvesting (L2 Ch4 L1) offsets capital gains and up to $3K of ordinary income annually.

Deferred-Comp Election Under IRC §409A

Senior executives with non-qualified deferred compensation plans subject to §409A can sometimes elect distribution timing (subject to plan rules; election must be made at least 12 months before the distribution year per §409A's plan-document and election rules). Stretching distribution out over multiple years smooths income; bunching into a single year (when other income is low) maximizes bracket utility.

QCD Coordination Under IRC §408(d)(8)

For 70.5+ charitable households, QCD directly reduces AGI (vs taxable RMD + itemized deduction which doesn't reduce AGI). 2026 QCD limit ~$108K per individual. The L3 Ch3 L1 RMD calendar's QCD-eligibility flag feeds this analysis. QCD's AGI-reduction cascades to IRMAA tier management.

HSA Above-the-Line Reduction

HSA contribution ($4,000 single / $8,300 family for 2026 + $1,000 catch-up if 55+) is above-the-line AGI reduction. Maintaining HSA contributions during high-income years contributes to AGI management. Pre-Medicare-enrollment (before age 65) HSA contributions remain available; post-enrollment, no further HSA contributions (existing balance continues to grow tax-free).

Business Income, Charitable Bunching, Other Levers

For business owners, S-corp salary vs distribution flexibility, retirement plan contributions timing, depreciation election strategy. For charitably oriented households, charitable bunching with DAF (lump-sum contribution to DAF, deduction in year-of-contribution, grant-out over multiple years) shifts itemized deduction into a single year. Tax-loss harvesting (L2 Ch4 L1) layers in.

The Integrated Memo — Multi-Workflow Capstone

The L3 Ch4 L2 deliverable is the multi-year integrated memo per household. The Hendersons example: 2026 — higher earner age 64 delaying SS, lower 62 considering early claim; Roth conversion $74K (L3 Ch2 L2) per Tier 2 IRMAA position; capital gain harvesting at 0% bracket since AGI low; no QCD (under 70.5); HSA $8,300 contribution; bridge cash flow from portfolio; projected 2028 IRMAA = Tier 2 from 2026 AGI ~$225K post-conversion. 2027 — similar mix; reassess if income changes. 2028-2029 — continued aggressive Roth pre-claim; capital gain harvest opportunities. 2030 — higher earner still delaying; conversion continues moderately. 2031-2032 — SS-claim years; conversion tapers; IRMAA tier 2-3 likely from elevated AGI; potential life-event appeal under Form SSA-44 if SS-start triggers material income increase. 2033+ — RMD-era; QCD coordination begins (when 70.5+ reached); steady-state IRMAA management.

The memo synthesizes Social Security, Roth conversion, RMD calendar, capital gains, QCD, HSA, and IRMAA into a unified four-year projection. The client sees a single coordinated picture rather than disparate memos. The senior advisor's judgment narrative captures the multi-workflow trade-offs and the IPS-aligned strategy.

Worked Example: The Hendersons — 2024 AGI to 2026 IRMAA Bracket Math

Robert (64) and Margaret (62) Henderson have $2.4M aggregate ($1.4M IRA for Robert, $400K Roth jointly, $500K joint brokerage, $100K HSA balance). Robert retired from his corporate role December 2023; Margaret continues part-time consulting ($35K). The household's 2024 1040 (extracted via Holistiplan in February 2025) shows: Margaret's Schedule C $35K; Robert's severance and final-year W-2 $145K; pension $42K; portfolio interest and dividends $48K; long-term capital gains $22K (from a December tax-loss-harvest rebalance that produced net gains); a 2024 Roth conversion of $96K executed in November after the advisor confirmed the projected AGI. The 2024 AGI lands at $388K. Under the 2026 CMS IRMAA tables (2024 AGI determining 2026 premiums), $388K places Robert in Tier 3 ($322K-$386K) — except the 2024 AGI marginally exceeds the $386K Tier 3 ceiling, pushing the Hendersons into Tier 4 ($386K-$750K). Robert turns 65 in April 2026 and enrolls in Medicare; Margaret is not yet Medicare-aged.

The 2026 IRMAA cost: Tier 4 surcharge of approximately $385/month Part B + $74/month Part D = $459/month × 9 months (April-December) = approximately $4,131 for Robert alone in 2026. If Margaret had been Medicare-aged, the cost would have doubled to $8,262. The cliff cost: had the November 2024 conversion been sized $2,500 smaller ($93,500 instead of $96,000), 2024 AGI would have been $385,500 — below the Tier 4 threshold — saving approximately $1,600 for 2026 alone. The lesson the advisor draws: every Roth conversion sized in the final quarter of any year is sized with the 2-year-forward IRMAA bracket map open on the second monitor, not as an afterthought.

Looking forward to the 2025 1040 (which determines 2027 IRMAA), the advisor projects: no W-2 income for either spouse (Robert fully retired; Margaret winding down consulting to $18K); pension $42K; portfolio income approximately $55K; planned 2025 Roth conversion sized to $128K (to fill toward top of 24% bracket while staying below $258K Tier 2 cap of the IRMAA structure that will apply to 2027). Projected 2025 AGI: $243K. 2027 IRMAA tier: Tier 1 ($206K-$258K). The conversion size was deliberately constrained to preserve Tier 1 — sizing it $20K larger would have produced approximately $1,500 of additional 2027 IRMAA cost per spouse, eroding most of the conversion's marginal tax-rate advantage. The integrated memo presents this trade-off explicitly so Robert and Margaret can confirm the policy choice.

The SSA-44 Life-Changing Event Appeal — Mechanics and Timing

Form SSA-44 ("Medicare Income-Related Monthly Adjustment Amount — Life-Changing Event") is the formal mechanism by which a Medicare beneficiary requests SSA to substitute current-year (or anticipated current-year) income for the default two-year lookback. The eligible life-changing events listed on the form are explicit: marriage, divorce, death of spouse, work stoppage (including retirement), work reduction, loss of income-producing property (not through sale or transfer), loss of pension income, and employer settlement payment. The form requires documentation appropriate to the event (death certificate, divorce decree, employer letter, etc.) plus the most recent tax return and an estimate of current-year MAGI.

The workflow application: when a client retires mid-year, the advisor immediately files SSA-44 to substitute the post-retirement income for the prior-year W-2-heavy AGI. The timing matters — SSA-44 can be filed at any time during the year, and successful appeals are usually retroactive to January (or the Medicare enrollment date if mid-year). For Robert Henderson, the SSA-44 opportunity arises in 2026: although 2024 AGI of $388K determines his 2026 Tier 4 placement, his 2024 work-stoppage event (December 2023 retirement, with first full year of no W-2 in 2024 partially offset by severance) likely qualifies. The advisor prepares the form in February 2026, attaches Robert's HR letter confirming the December 2023 retirement and the severance allocation, attaches the projected 2026 MAGI of approximately $220K (well below Tier 1 cap), and submits via Robert's local SSA office. Outcome (typical, based on the advisor's experience across the household base): SSA grants the appeal within 6-10 weeks, retroactively adjusts the April-onward Medicare premiums to Tier 1 ($206K-$258K, approximately $83/month), and refunds the difference. Total recovered: approximately $3,000 for Robert's 2026 IRMAA — paid back via reduced Social Security check withholding.

The L3 Ch4 L2 workflow's regulatory checkpoint includes an SSA-44 candidate flag for any household where (a) a life-changing event occurred in the past 24 months, AND (b) current-year projected MAGI is at least one IRMAA tier below the default lookback tier. The flag generates an action item; the advisor files the form; the appeal outcome is tracked through resolution and the recovered amount is documented in the household's planning record.

The Roth-Conversion-vs-IRMAA Tension at Named Bracket Numbers

The deepest planning tension in the post-retirement / pre-RMD window is between Roth conversion size (which wants to fill bracket capacity at currently-known low rates) and IRMAA tier preservation (which wants AGI capped below the next tier threshold). The trade-off math at named 2026 bracket numbers, MFJ: federal 24% bracket runs from $206,700 to $394,600 taxable income (after standard deduction of $30,000 = AGI range approximately $236,700 to $424,600); 32% bracket from $394,600 to $501,050 (AGI range approximately $424,600 to $531,050). The 2028 IRMAA Tier 1 cap (likely, indexed): approximately $215K MFJ; Tier 2 cap approximately $268K; Tier 3 cap approximately $335K; Tier 4 cap approximately $400K. The conversion-sizing decision sits at the intersection.

For a household projected to be in retirement for 8-12 more years before RMDs begin, the question is: pay 24% federal now on a $100K conversion plus $2,500 per spouse IRMAA penalty (effective rate approximately 26.5%), or defer the conversion and face 22% (or higher under future-legislation risk) on RMDs starting age 73-75? The breakeven calculation is sensitive to assumed future marginal rate, IRMAA persistence, growth rate of the converted dollars, and bequest planning (Roth dollars to non-spouse beneficiaries face the 10-year stretch but produce tax-free distributions). The advisor's integrated memo models the breakeven explicitly per household; for Robert and Margaret, the model recommends staying within Tier 2 ($258K AGI cap → approximately $128K-$160K annual conversion depending on baseline income) for 2025-2030, then accelerating in 2031-2032 if MAGI naturally drops, with the explicit policy that no conversion is sized to push into Tier 4 absent specific household-level rationale.

The Handoff Diagram and Three-Tier Verification

Source-system: AGI history from Holistiplan-extracted 1040s; RightCapital plan projecting future AGI; SSA portal benefits; aggregated IRA balances and RMD projections from L3 Ch3 L1; current CMS IRMAA threshold tables; HSA contribution status; business income projections (if applicable). Regulatory: CMS IRMAA threshold publication for relevant years; IRC §408(d)(8) QCD; IRC §409A deferred-comp election rules; capital gain bracket thresholds for relevant year; HSA limits; Form SSA-44 appeal eligibility criteria. Client-fit: IPS retirement-income policy; client's charitable orientation; documented preferences on tax-bracket management; bridge cash-flow capacity; life-event triggers; multi-workflow coordination explicitly addressed.

The Deliverable and Archive

The L3 Ch4 L2 memo per household: (1) two-year forward AGI projection with sensitivity analysis; (2) IRMAA tier projection per year with cliff identification; (3) income-smoothing levers deployed per year (Roth conversion size, capital gain harvesting target, QCD coordination, HSA contribution, deferred-comp election if applicable, other); (4) multi-workflow integration table showing Roth + RMD + SS + IRMAA + capital gains + charitable + HSA per year; (5) the Reg BI Care narrative documenting the multi-lever rationale and alternatives; (6) the client-facing memo translating the integrated picture into household language; (7) tagged-Markdown Smarsh archive per L2 Ch8 L2.

The CCO sampling under FINRA Rule 3110 examines the integrated memo's multi-workflow coordination quality — does the memo demonstrate explicit coordination across Roth, RMD, SS, IRMAA, gains, charitable, HSA? Does it capture the alternatives considered for each lever? Does the Reg BI Care narrative document the application of judgment across the integrated picture?

Key Takeaways

• IRMAA is a step-function cliff tied to AGI two years prior. 2026 IRMAA tier from 2024 AGI; 2027 from 2025 AGI; 2028 from 2026 AGI. CMS publishes annual tier thresholds in late Q4 of prior year.
• 2026 IRMAA tiers (illustrative MFJ): Tier 0 ≤ $206K; Tier 1 $206K-$258K (~$1K/person/year incremental); Tier 2 $258K-$322K (~$2.5K); Tier 3 $322K-$386K (~$4K); Tier 4 $386K-$750K (~$5.5K); Tier 5 above $750K (~$6K).
• Form SSA-44 life-event appeal allows current-year IRMAA tier recalculation when material life-events (retirement, death of spouse, divorce, work stoppage, pension loss) reduce income; flag candidates in the workflow.
• The income-smoothing toolbox: Roth conversion timing (L3 Ch2), capital gain harvesting (0% LTCG bracket in low-income years), deferred-comp election (IRC §409A; 12-month advance election), QCD coordination (IRC §408(d)(8); 70.5+; $108K 2026 limit), HSA above-the-line ($4K single / $8,300 family 2026 + $1K catch-up 55+), business income flexibility, charitable bunching with DAF, tax-loss harvesting (L2 Ch4 L1).
• The integrated memo synthesizes Social Security + Roth + RMD + capital gains + QCD + HSA + IRMAA into a unified four-year projection — the multi-workflow capstone the L3 Ch4 sequence delivers.
• Hendersons multi-year integrated plan: 2026-2029 aggressive Roth + capital gain harvesting + HSA + Tier 2 IRMAA preservation; 2030 moderate; 2031-2032 SS-claim with possible SSA-44 appeal; 2033+ RMD-era + QCD coordination.
• Three-tier verification: source-system (Holistiplan + RightCapital + custodian + CMS thresholds + HSA status); regulatory (CMS IRMAA + IRC §408(d)(8) QCD + §409A deferred-comp + LTCG bracket + HSA limits + SSA-44 eligibility); client-fit (IPS + charitable orientation + tax-bracket preferences + bridge cash flow + life-events + multi-workflow coordination).
• The deliverable: two-year AGI projection + IRMAA tier projection + income-smoothing levers per year + multi-workflow integration table + Reg BI Care narrative + client-facing memo. CCO sampling examines integrated memo coordination quality. The L3 Ch4 sequence completes here; L3 Ch5 (next) opens with Estate Document Intake.