Fielding MSLs vs. Building a Field Medical Program

MSLs are among the most expensive per-headcount investments in biopharma. Advanced-degree professionals with deep therapeutic expertise, significant training investment, and substantial travel footprints. The industry has poured further resources into making them more effective: scientific training programs, communication skills development, KOL engagement coaching, congress preparation, CRM training. Professional societies have built competency frameworks, certification pathways, and best practice guidelines.

All of that investment targets the individual MSL. How skilled is she? How prepared is he? How effective are they in the field?

Now ask the organizational question: How mature is the function that deploys them?

Not the individuals — the function. How does the organization decide how many MSLs to hire? How does it differentiate roles beyond seniority titles? How does it design career paths that retain its best scientific contributors? How does it structure the team to match the product lifecycle — launch-stage intensity versus mature-product depth? How does it avoid credibility-eroding situations — like multiple MSLs from the same company approaching the same KOL with different products (mirrored field teams)?

And the deeper question: does MSL strategy define what the role should do — what meaningful scientific exchange looks like for this team, this product, this stage — or does it simply default to whatever activities remain after legal, regulatory, and compliance review strips away the "risky" ones?

Most organizations have detailed answers to the first set of questions and improvised answers to the second. That asymmetry — heavy investment in individual capability, minimal investment in organizational architecture — is the gap this piece is about.

The Distinction

Two concepts that sound related but are structurally different.

Individual competency is what the industry has invested in. It answers: Can this MSL engage a KOL effectively? Does she understand the mechanism data? Can he handle an unsolicited off-label question compliantly? Does she document interactions properly? The professional societies have built robust frameworks for this — competency surveys, training curricula, certification programs. 72 of 191 sources in the MSL literature address it. This layer is well-developed.

Organizational maturity is what the industry has largely skipped. It answers: Does the function have differentiated roles or just seniority adjectives? Is the team structured for its current product lifecycle phase? Do career paths exist that don't force scientific contributors into management? Is territory design driven by strategic inputs or by geography and convenience? Does the function operate reactively — responding to ad hoc requests, defining the MSL role as whatever's left after compliance review — or strategically, with activities flowing from a scientific platform that defines what meaningful scientific exchange looks like? Does the field medical team have a clear and unique purpose, or is it defined entirely by what it is not — non-promotional, non-commercial, non-sales?

The distinction matters because you can have a team of individually excellent MSLs inside an organizationally immature function. They'll each be effective in front of a KOL — assuming you don't cripple them with limitations on meaningful scientific conversations and resources. But their territories were drawn on a map. Their priorities were self-directed and constantly shifting, or worse, borrowed from commercial. Their career paths dead-end at Senior MSL unless they want to manage people. Their insights go into a CRM — if they're allowed free text — and never come back out. The function's definition of the MSL role amounts to whatever's left after compliance review — reactive Q&A rather than proactive, meaningful scientific exchange. The individuals are performing. The function isn't progressing.

Here's how the difference shows up in practice. When practitioners say the function needs HEOR capability, the organizational response matters. An immature function hears "we should do HEOR training for our MSLs." A mature function asks a different question: "How do we strategically leverage therapeutic-area MSLs in payer engagements — or should we layer in a differentiated HEOR MSL function?" Same input, fundamentally different organizational response. The first is an individual competency fix. The second is an organizational architecture decision.

If you've ever felt the difference between "my MSLs are great" and "my MSL program is great" — this is the distinction. One describes the people you hired. The other describes what you built around them.

What Organizational Maturity Actually Looks Like

"Maturity" sounds abstract. It isn't. It describes a progression that's visible in the day-to-day decisions a field medical function makes — how it plans, how it deploys, how it equips, and how it connects to the broader medical affairs strategy.

Reactive (Levels 1–2). MSLs respond to requests. Engagement is ad hoc — whoever calls, whatever comes up. Territory design mirrors sales geography. The career ladder is MSL → +/- Senior MSL "title" → Manager. Metrics are activity-based. The team exists, but it's a collection of individuals rather than a coordinated function. When leadership asks "what did the MSL team accomplish this quarter?" the answer is a list of activities, not a set of outcomes. Internal stakeholders don't fully see the value — MSL headcount and budget face pushback because nobody can articulate the return. Commercial leadership leans in to pressure MSLs to "do more."

Planned (Levels 3–4). The function has structure. POAs exist and may have stated objectives. KOL tiering is formalized. Territory design considers KOL density, academic medical centers, and research sites — not just geography. But the planning is often disconnected from medical affairs strategy. The POA was written in a vacuum — looking at what activities the team did last cycle and trying to increase quantity from there. If a scientific platform exists, it doesn't cascade to individual priorities. The metrics are still largely activity-based even if the planning is more deliberate. There is internal support for the MSL team, but the focus tends to be on days-in-field, touchpoint counts, and whether the MSLs are "getting along" with their commercial counterparts. The function is organized, but the connection between strategy and field execution is loose. Commercial and medical leadership perceive the team as having effective and ineffective MSLs — which results in pressure on team leadership to micromanage, or defaults to yet another round of individual MSL effectiveness training.

Strategic (Levels 5–6). Activities flow from the scientific platform through a deliberate cascade. Roles are differentiated where the science demands it — therapeutic MSL vs. HEOR MSL, for example — rather than through generic adjectives. Career levels — MSL, Senior MSL, Principal MSL — signal that the company is genuinely invested in the program and has built progression paths for both management and deep scientific contribution, not just differentiated titles that do more of the same work. The POA is differentiated based on where the product and scientific platform sit in their lifecycle. A novel mechanism demands a different field plan than an established brand.

Resources and materials are tied directly to the scientific platform — FAQs on challenging issues, competitive data, content aligned to the questions the field is actually hearing and where the science is moving — rather than a generic on-label slide deck built around the package insert. Mature MSLs understand fair and balanced scientific exchange and are trusted to tailor content to the specific situation. In contrast, immature functions require rigid adherence to presenting all approved content regardless of context. The goal should be at least a robust reactive content set — and, depending on the company's position on scientific exchange, a proactive one.

Every MSL can explain how their current priorities connect to the scientific platform and MSL program objectives. Internal stakeholders understand the MSL value proposition and how it's differentiated from internal medical affairs and field commercial.

Ecosystem (Level 7+). Field medical insights directly influence medical strategy, evidence generation planning, and scientific platform refinement. The feedback loop from the field to the C-suite is systematic, not anecdotal. The field medical team occasionally comes up in quarterly earnings calls. The function isn't just aligned with medical affairs strategy — it shapes it. Everyone wants to know what the field is hearing. Outcomes are defined and measured — they are the team's focus, not activity KPIs. MSL program leadership can demonstrate impact, both in absolute terms and relative to competitors.

Most organizations self-assess higher than they are. A formalized POA feels like Level 5. It's usually Level 3. The difference is whether planning is connected — whether there's a traceable line from scientific platform to Tuesday afternoon. Structure without connection is organization, not maturity.

And a point worth making explicitly: size doesn't equal maturity. A 10-person team can operate at Level 5. A 50-person team can be stuck at Level 2. Maturity is about how the function is architected, not how many people it employs — or how many career levels you bolt on to keep your best MSLs from jumping ship when the plans stay tactical.

The Signals

Not every field medical leader has the time or inclination to map their organization against a maturity model. But a handful of signal questions can locate you roughly — enough to know whether the distinction in this piece is academic or urgent.

You're likely at Levels 1–2 if your MSLs describe their role primarily as "being available" for KOLs. Territory plans are inherited from predecessors or the prior cycle with minimal redesign. The primary metric in your monthly report and QBR is interaction count. Your best MSL and your newest MSL have the same job description, maybe differentiated by "Senior" in the title. When someone leaves, you replace them with the same role in the same territory. Stakeholders push back on MSL headcount and budget because they don't see the value.

You're likely at Levels 3–4 if you have a POA with stated objectives but you'd struggle to trace those objectives back to the medical affairs strategy or any scientific platform. KOL identification and tiering is formalized, but territory assignments were designed around large cities and MSAs or where MSLs live. You've thought about differentiated MSL competencies and may have even added a Principal MSL track. Insights are collected ad hoc, but you couldn't name the top three themes from last quarter without checking the CRM or manually polling the team. Execs want to ride in the field to "see what's going on." There's internal support for the MSL team, but the focus is on days-in-field, touchpoints, and whether the team is "getting along" with sales.

You're likely at Levels 5–6 if every MSL can explain how their current priorities connect to the scientific platform and MSL program objectives. Roles are differentiated by operating model, not just seniority. You measure qualitative outcomes alongside activity metrics. Territory design is reviewed when the strategic landscape changes — not just when someone leaves or budgeted headcount shifts. Field insights are regularly surfaced and impact strategy. Internal stakeholders understand the MSL value proposition and how it's differentiated from internal medical affairs and field commercial. Execs want to ride in the field to leverage MSL relationships and insights.

If you want the full picture, the Maturity Assessment maps your organization across all three pillars in about five minutes.

The Foundation Everything Else Depends On

Organizational maturity isn't an isolated concern. It's the foundation that planning and measurement depend on.

A field medical function stuck at Level 2 can't effectively implement a planning cascade — there's no organizational structure to cascade into. It can't measure qualitative outcomes — there's no framework for defining what outcomes to look for. Organizational maturity is the foundation that the other two pillars build on.

This is why the maturity model sits at the center of MSL Blueprint's framework. It's not just a diagnostic. It's the organizing principle that determines which planning methodologies and measurement approaches are appropriate for where your organization actually is — not where you think it is or where you want it to be.

If the distinction in this piece resonates — if you recognize the gap between how much you've invested in your MSLs and how much you've invested in the function around them — the next step is knowing exactly where you are. The Maturity Assessment takes five minutes and maps your organization across all three pillars. If you want to see what one specific dimension of organizational maturity looks like in practice — how scientific strategy should cascade from platform to field execution — The Scientific Platform Cascade maps it out.

Start by knowing where you are.

The author is the founder of MSL Blueprint and has spent the last 20 years building, leading, and scaling field medical teams at several biopharmaceutical companies — from team design and territory optimization through scientific platform strategy, KOL engagement frameworks, and qualitative outcome measurement. MSL Blueprint is building the strategic planning and measurement layer that the field medical function has been missing since 1967.

Related reading: - The Scientific Platform Cascade: How Strategy Should Flow to the Field - The Standardization Gap: 1967 to 2026 and Still No Playbook - Planning in the Blue Ocean: Why Nobody Has Solved MSL Territory Planning - The 6% Problem: Why Activity Metrics Fail MSL Leaders