Part D Redesign 2025-2026: The End of Copay Accumulators and the New Patient Economics

TL;DR

Thesis

Part D redesign moves Medicare affordability from manufacturer-funded copay relief to statutory benefit design and mandatory manufacturer discounts. The $2,000/$2,100 OOP cap and M3P smoothing reduce patient cost shock, but MDP shifts a large, unavoidable rebate-like liability onto manufacturers. The resulting services thesis is not “less patient support.” It is a shift from Medicare copay-card administration toward M3P routing, foundation coordination, adherence, GTN reconciliation, and separate commercial accumulator mitigation (CMS Part D redesign instructions; Drug Channels accumulator/maximizer analysis; Milliman M3P analysis).

The central buyer implication is payer-type bifurcation. Medicare Part D patients now need different workflows from commercial patients: no manufacturer copay cards, lower bounded OOP exposure, M3P/foundation navigation, and MDP economics. Commercial patients still require copay cards, accumulator/maximizer detection, and plan-specific benefit design. Hubs, copay processors, and GTN platforms that continue to operate a single affordability workflow will misallocate budget.

Old Part D vs. New Part D

The pre-2025 Part D benefit had four sequential phases: deductible, initial coverage, coverage gap (the “donut hole”), and catastrophic. Manufacturer liability was concentrated in one phase, via the Coverage Gap Discount Program (CGDP), which required a 70% discount on brand drugs while the patient was in the donut hole. Beneficiary out-of-pocket had no annual cap. A patient on a $100,000 specialty drug could spend $6,000 to $12,000 or more per year.

Phase	Enrollee share	Plan sponsor	Manufacturer (MDP)	CMS reinsurance
Deductible ($590 in 2025, $615 in 2026)	100%	0%	0%	0%
Initial coverage	25%	65%	10%	0%
Catastrophic (after $2,000 / $2,100 TrOOP)	0%	60%	20%	20%

Two features matter most for manufacturers. First, CMS reinsurance in the catastrophic phase fell from 80% (pre-2024) to 20% for applicable drugs. The ~60 points of risk that shifted off CMS landed on plan sponsors, who responded with tighter formularies and more aggressive utilization management on non-negotiated drugs. Second, MDP does not count toward the beneficiary’s true out-of-pocket (TrOOP) accumulation. Under the old CGDP, the 70% manufacturer payment did count toward the out-of-pocket threshold.

How MDP Rewrites Manufacturer GTN

MDP is the sleeper story of the redesign. On paper it is a replacement for CGDP. In practice, it is a structurally larger rebate with a different distribution curve. Under CGDP, only the subset of Part D patients who entered the coverage gap triggered manufacturer liability, and catastrophic had no manufacturer obligation at all. Under MDP, every applicable Part D claim in the initial coverage and catastrophic phases carries a manufacturer discount. That flips the question from “what share of my Part D patients reach catastrophic?” to “what is my total Part D applicable-drug volume?” The answer is almost always larger.

For high-cost Part D specialty drugs, the MDP can become a major per-patient gross-to-net line because the manufacturer discount now applies in both the initial coverage and catastrophic phases under CMS’s Part D redesign instructions.

Drug archetype	Pre-IRA manufacturer obligation	Post-IRA MDP direction
Lower-cost specialty	Concentrated in the coverage gap when reached	New initial-coverage discount plus catastrophic discount if reached
High-cost specialty	Coverage-gap discount for the subset and timing that reached the gap	Larger recurring obligation across applicable-drug volume
Very high-cost specialty	Coverage-gap discount, with no manufacturer obligation in catastrophic	MDP becomes one of the central GTN model lines

GTN models that treated the old coverage-gap discount as a minor rebate line must be rebuilt. Manufacturers need to reconcile MDP claims through the TrOOP Facilitation Contractor and plan sponsor invoicing chain. Pfizer disclosed an approximately $1.5 billion annual manufacturer mandatory-discount headwind, partially offset by an expected $500 million volume benefit, for about a $1 billion net unfavorable 2025 revenue impact from Part D redesign.

Why Copay Accumulators and Maximizers Lose Value in Medicare

Copay accumulators and maximizers are commercial insurance mechanisms. They operate on manufacturer copay cards, which are not legally available to Medicare beneficiaries because federal Anti-Kickback Statute interpretation bars manufacturer cost-sharing assistance for government-reimbursed drugs. Medicare beneficiaries were never the direct target. But they were the indirect victim of the old Part D structure: without copay cards, without a cap, and with a coverage-gap discount that counted toward TrOOP, beneficiaries on high-cost specialty drugs often paid thousands out of pocket and abandoned therapy at the gap.

Post-redesign, the $2,000 cap ends this dynamic for Medicare. The accumulator question is moot because there is no copay card to accumulate. The maximizer question is moot because there is nothing to drain. Foundation dollars can be reserved for needs that remain after the Part D cap, including premiums, transportation, and other non-drug affordability gaps.

The three big PBMs all operate accumulator or maximizer variants. Express Scripts (Cigna, operator of Accredo) runs SaveOnSP. CVS Health / Caremark runs its Accumulator Adjustment Program and Copay Assistance Tracker. Optum Rx runs Copay Assist Management. Drug Channels / MMIT describe commercial accumulator and maximizer exposure as a live commercial-market issue, not a Medicare issue. The strategic implication: accumulator mitigation budget should shift almost entirely to commercial lives. The “Medicare copay” line item is mostly obsolete. Vendors with dynamic, plan-aware copay adjudication, including TrueConnect at ConnectiveRx, PillarRx, and platforms operated by Phil and Valeris, are positioned to absorb reallocated spend.

Smoothing (M3P) Implementation

M3P, or “smoothing,” lets a Part D beneficiary opt in to paying cost sharing in monthly installments rather than at the pharmacy counter. The plan sponsor pays the pharmacy up front and bills the beneficiary each month. Enrollment is free, and any beneficiary may opt in during open enrollment or any time during the plan year.

M3P solves the January cost spike. Under the new benefit, a beneficiary starting a high-cost specialty drug in January can hit the $2,100 cap within weeks, paying essentially all annual out-of-pocket up front. Smoothing spreads that cost evenly across the year.

What M3P means for hub and specialty pharmacy operations

For hub services, M3P enrollment is a new intake workflow. Identifying whether a patient is likely to benefit requires drug-level and patient-level data: expected out-of-pocket trajectory, when the beneficiary will hit the cap, and whether monthly smoothing is materially better than their current cash-flow situation. Hub platforms including AssistRx, CareMetx-owned Lash/TheraCom, ConnectiveRx, and Eversana are best positioned to integrate M3P routing. TailorMed and Payer Sciences are building affordability-navigation logic that surfaces M3P alongside copay, foundation, and PAP paths.

For specialty pharmacies, M3P reduces January cash-flow shock. Under the new benefit, a beneficiary starting a high-cost specialty drug in January can hit the annual cap quickly; smoothing spreads that liability across the year instead of concentrating it at the counter. Operators should track whether lower point-of-sale burden improves January start rates, but most pharmacy-level abandonment metrics remain proprietary.

Impact on Pharma Services Vendor Categories

Category	Pre-redesign demand driver	Post-redesign demand driver	Net direction
Hub services	Copay admin, Medicare PAP intake, coverage-gap navigation	Enrollment, adherence, M3P routing, MDP reconciliation, matrix affordability	Mix shift; per-patient touch up, copay-admin FTE down
Copay processors (comparison)	Medicare PAP + commercial copay + accumulator mitigation	Commercial-only copay + aggressive accumulator mitigation	Medicare shrinks; commercial grows
Specialty pharmacies	January abandonment management; first-fill PA friction	Lower January abandonment; MFP margin compression	Volume up, per-fill margin down
Market access consulting	Rebate and contracting strategy	MDP-aware GTN, launch pricing optimization, indication sequencing, Part D vs commercial bifurcation	Strong growth
Data and GTN platforms	Rebate calculation, plan-level analytics	MDP claim settlement, TrOOP reconciliation, Part D risk modeling	Strong growth
Foundations and PAPs	High per-patient grants for Medicare specialty patients	Smaller grants reaching more patients; focus on premiums, transportation	Demand reshape

Hub services. Programs live under a “do more with less” mandate: Medicare patients face lower point-of-sale exposure, but manufacturer funding tightens under MDP GTN pressure. Hub vendors that automate M3P, PAP, foundation, and commercial copay in a single affordability workflow hold an advantage. The Hub Services Market Analysis covers the broader competitive landscape; the Hub Services Buyer’s Guide covers vendor selection.

Copay processors. Pre-redesign, a single program had to cover both commercial and Medicare populations. Post-redesign, the bifurcation is sharper: Medicare copay programs effectively cease (beneficiaries cannot use manufacturer copay cards and the cap bounds cost-sharing relief), while commercial programs carry the full weight of accumulator mitigation. Our copay processors comparison details vendor-level differences.

Specialty pharmacies. Net positive for volume, mildly negative for margin. Patients stay on therapy longer, especially in oncology, MS, and rare disease. Margin on any drug under Round 1 MFP (2026) or Round 2 MFP (2027) is structurally lower as the negotiated price narrows dollar-per-fill spread. See our Big Three PBM specialty pharmacies analysis.

Market access consulting. GTN rebuild is now a core workstream for Part D-exposed brands. Trinity Life Sciences, Avalere, ZS Associates, and Lumanity are natural shortlist candidates for Part D exposure modeling, commercial spillover analysis, and IRA-aware launch pricing. See our market access consulting overview.

Data, analytics, and GTN platforms. MDP settlement is operationally complex. The TrOOP Facilitation Contractor sits between plan sponsor and manufacturer, and claims must be reconciled against applicable-drug status, MFP exemption, and benefit phase accounting. IntegriChain, Model N, and IQVIA revenue-management have each built MDP modules. Evidence-side demand for Komodo, MMIT, and IQVIA extends into CMS negotiation data work. See Pharma Services Explained for category boundaries.

Medicare vs Commercial Program Split

The redesign forces manufacturers to stop treating “affordability” as one operating lane. Medicare and commercial assistance now require different vendor workflows:

Workflow	Medicare Part D	Commercial insurance
Cost-sharing relief	M3P, LIS, foundation, PAP, premium support where allowed	Copay card, e-voucher, debit / alternate-payment vehicle, bridge
Accumulator / maximizer exposure	Not applicable because manufacturer copay cards cannot be used	Central risk; requires accumulator detection, dynamic benefit design, and state-law logic
Manufacturer economics	MDP, MFP-year selected-drug subsidy mechanics, adherence ROI	Rebates, copay spend, accumulator leakage, commercial GTN
Vendor KPI	M3P enrollment, foundation completion, persistence after cap, abandonment reduction	First-fill conversion, accumulator detection, patient OOP, abandonment, refill persistence
Data handoff	TrOOP, plan sponsor, foundation, hub, SP, MDP settlement	PBM accumulator flags, copay redemption, eBV/ePA status, SP fill data

The practical procurement implication is that a copay vendor strong in commercial accumulator mitigation may not be the right Medicare affordability-navigation partner. Conversely, a hub with excellent M3P / foundation routing may still need a separate commercial copay processor with stronger plan-level accumulator intelligence.

What Launch Teams Should Do in 2026 and 2027

Four concrete changes for any product with meaningful Part D exposure.

1. Rebuild the GTN model to treat MDP as a primary line item. A pre-IRA GTN stack modeled commercial rebates, Part D rebates, CGDP, 340B chargebacks, Medicaid best-price rebates, and copay spend. MDP either did not exist or was rolled into “government rebates.” Post-redesign, MDP needs its own line, computed per applicable-drug claim, split across initial coverage (10%) and catastrophic (20%) phases, with MFP-year exemption logic. Standard path: consulting with Trinity Life Sciences, IQVIA, or Avalere, plus implementation in IntegriChain or Model N.

2. Remove Medicare copay-card assumptions and redirect budget. Beneficiaries cannot owe more than $2,100 in 2026, and they cannot legally use manufacturer copay cards for Medicare-reimbursed drugs. Freed budget is better deployed in commercial accumulator mitigation or adherence programs that justify the MDP obligation.

3. Bake M3P navigation into hub intake. Hubs should flag patients likely to hit the cap early, explain smoothing, and route to plan enrollment. AssistRx, CareMetx-owned Lash/TheraCom, ConnectiveRx, Eversana, and TailorMed are the hub / affordability operators to diligence for 2026 intake-script support. For a 2026 or 2027 launch, this is table stakes.

4. Treat foundations as the Medicare safety net. Coordinate with HealthWell Foundation, Accessia Health, and PAN Foundation on updated eligibility thresholds, award sizes, and non-drug affordability gaps. Foundation capacity should be positioned for the first-quarter crush before M3P auto-renewal catches up.

Summary of Unit Economics Changes

For a hypothetical Part D-heavy specialty brand, the direction of travel is clear:

Line item	Pre-IRA model	Post-IRA model
Medicare copay card spend	Often modeled even when legally constrained	Removed or sharply reduced for Medicare
MDP obligations	Not applicable	Primary GTN line item
Foundation / PAP support	High per-patient cost-sharing relief	More targeted safety-net support
Hub copay administration	Heavier Medicare copay operations	Lower Medicare copay-card workload
Hub enrollment / adherence / M3P	Secondary workflow	Core Medicare workflow

The strategic answer is not to minimize MDP (which is mandatory) but to maximize adherence and persistence to justify the MDP cost the manufacturer is already paying. This reframes the role of the hub and the specialty pharmacy in a way most 2024 brand plans did not fully anticipate.

Implications

Manufacturers should rebuild copay and hub budgets around Medicare/commercial segmentation. Medicare copay-card maximums should be eliminated or sharply reduced where legally inapplicable, while commercial accumulator mitigation and adherence support should receive more targeted funding. Hub intake should flag Part D patients for M3P, LIS, foundation, PAP, and adherence workflows rather than attempting to force them through commercial copay logic.

Vendor diligence should test whether the platform can compute benefit-phase exposure, identify likely cap timing, route patients into smoothing, and reconcile MDP/TrOOP data with GTN systems. For specialty pharmacies, lower January abandonment can lift volume, but MFP and MDP mechanics compress economics; contracts should separate dispensing fees, clinical services, and data/reporting value rather than assuming acquisition spread funds the service layer.

Outlook

Three developments reshape the picture between now and 2028. First, MFP takes effect for Round 1 Part D drugs in 2026 and Round 2 drugs in 2027. For those drugs, MDP is paused in the MFP year and a new selected drug subsidy program applies. Second, M3P auto-renewal starts in 2026; uptake should rise substantially, and hubs that have not integrated M3P routing by mid-2026 will underperform peers on January start rates. Third, federal action on commercial copay accumulators remains possible. The HHS rule on whether copay assistance must count toward the ACA annual out-of-pocket maximum has been litigated, and congressional action on an “All Copays Count” federal standard has bipartisan support but uncertain timing. A federal ban would not affect Medicare but would meaningfully reduce PBM revenue from accumulator programs on commercial lives.

The core insight is durable. For Medicare Part D, the benefit is now structurally protected from the worst abuses of cost-sharing design. Manufacturer economics have shifted from “pay copay, recover formulary position” to “pay MDP, maximize adherence.” The copay accumulator battleground of the mid-2020s now lives entirely on the commercial side of the book. Launch teams that recognize this bifurcation and rebuild their programs accordingly will outperform. Those that treat Medicare and commercial as a single copay segment will overspend on Medicare and underspend on commercial accumulator mitigation, the exact opposite of what the new economics require.

Related Reading

• Hub Services Market Analysis
• Hub Services Buyer’s Guide
• Copay Processors Comparison
• Market Access Consulting
• Big Three PBM Specialty Pharmacies
• Pharma Services Explained: Hub, Specialty Pharmacy, FRM

Analysis compiled April 2026. Regulatory figures verified against CMS Final CY 2025 and CY 2026 Part D Redesign Program Instructions. Market prevalence figures for copay accumulators and maximizers sourced from IQVIA and Avalere 2025 publications. First-year M3P uptake data from IQVIA and Milliman (mid-2025). Vendor-specific claims reflect publicly disclosed product capabilities as of Q1 2026.