Rare disease drugs are concentrating self-funded pharmacy spend in a few members

Limitless Consulting says a small set of orphan drugs can shift more than $1 million in annual cost to a self-funded health plan for a single member. The company is offering no-cost renewal analyses through the 2027 renewal season as employers face rising specialty-drug pressure and more scrutiny of pharmacy pricing.

Why it matters: - Rare disease drugs are now a major driver of self-funded pharmacy spend. - One member on one orphan-class therapy can dominate a plan’s drug budget. - Employers often only have one practical chance to change plan language at renewal. - The issue matters because plan sponsors still have to cover clinically necessary care, but the payment path can change the cost by hundreds of thousands of dollars.

What happened: - Limitless Consulting released an analysis of orphan drug costs on self-funded employer health plans. - The firm found that 10 rare disease medications commonly seen on employer claims files each account for $468,000 to $1.44 million a year in cost the plan does not have to absorb. - Palynziq showed the highest annual figure at $1.44 million. - Miplyffa followed at $1.40 million. - Strensiq came in at $1.15 million. - Lumizyme came in at $948,000. - Takhzyro showed the lowest annual figure in the group at $468,000. - The analysis was released in Colorado on Aug. 18, 2026.

The details: - Limitless Consulting evaluates high-cost medications across 9 optimized sourcing channels. - For orphan drugs, the firm’s Foundation program uses supplemental coverage to cover the medication cost. - Every medication is dispensed inside the United States. - The Foundation program does not import drugs from another market. - The employer keeps its PBM, carrier and network. - The program runs alongside the existing plan structure. - Limitless administers a coverage route that moves the medication off the employer’s plan. - Enrollment and member support are handled by the program instead of the employer’s staff. - The employer plan pays $0 for the drug. - The member pays $0. - Eligibility is based on drug classification. - An orphan drug treats a condition affecting fewer than 200,000 Americans. - Congress created the orphan designation in the Orphan Drug Act of 1983. - The FDA approved 50 novel drugs in 2024, and 26 were for rare diseases. - In 2025, 25 of 46 novel approvals carried orphan designation. - Optum reports a median launch price of $218,872 a year for orphan drugs, versus $12,798 for other drugs. - Gene therapies can cost $1 million to $3 million. - Mercer projects a 6.7% employer health cost increase for 2026, the highest in 15 years. - Mercer says costs are passing $18,500 per employee. - Pharmaceutical Strategies Group reviewed 204 million medical claims and found 5.5% of members used at least one specialty drug. - PSG said utilization drove 10.6 of the 10.8 percentage points of specialty trend. - Aegis Risk found 49% of self-funded plans had a claimant exceed $1 million in the prior 2 policy years. - A de-identified six-month impact report from a plan with 669 average employees showed 79 members assisted across 160 fills and 36 medications. - That report showed $995,232 in gross employer impact and $866,920 net of the $128,312 program cost. - One member on an orphan-class therapy accounted for 48.7% of the total. - The figures exclude rebate loss and stop-loss offset because neither was supplied for that plan. - The Foundation route requires an orphan drug exclusion in the plan document. - Midyear amendments are difficult to obtain, while renewal changes are routine. - Limitless is offering the same analysis on any self-funded plan’s claims at no cost through the 2027 renewal season. - Employers or consultants can send a claims file or a Top 25 drug list. - Limitless says a written analysis of every orphan and high-cost medication comes back in 1 to 3 business days. - There is no fee and no obligation. - If a current arrangement is already competitive, Limitless says that in writing. - Files can be submitted at LimitlessRxSolutions.com/get-started. - The company asks users to add Renewal2027 in the comments to claim the free analysis. - The de-identified impact report is available on request.

Between the lines: - The analysis frames orphan-drug strategy as a renewal issue, not a midyear savings tactic. - The pricing gap between a plan’s current payment path and alternative coverage routes can be extreme when just one member drives most of the spend. - The company is also signaling that employers should document their drug-purchasing process more carefully as ERISA litigation over prescription-drug costs advances. - Louis Gallucci said coverage is not the question; the question is what the plan pays and whether anyone ever reviewed alternatives. - Mike McLain said a generic trend response does not fix a cost problem concentrated in a few members on a few medications. - Limitless says a second effect is not included in its estimates: these members are often the plan’s largest claimants, so catastrophic exposure remains with the plan until the stop-loss carrier confirms it.

What's next: - Employers and consultants can submit claims files now for a complimentary renewal analysis. - The firm expects most plan changes, if any, to happen at renewal because plan-document amendments are difficult midyear. - The company says it will continue offering the review through the 2027 renewal season. - Legal pressure on drug purchasing and PBM-related plan spending is likely to remain part of the backdrop for plan sponsors.

The bottom line: - A handful of rare disease drugs can concentrate pharmacy spend so heavily that one member can carry nearly half of a plan’s orphan-drug exposure. - For self-funded employers, renewal may be the only realistic moment to change how that cost is paid.