Non-physician providers aren't taking over Medicare billing — they're actually losing ground. The share of unique advanced practice providers (NPs, PAs, CRNAs) relative to physicians in Medicare billing peaked in 2017 and has fallen every year since, dropping from a ratio of 0.030 to 0.026 by 2023.

Key Numbers

• 7,056 NPs, PAs, and CRNAs billed Medicare in 2013; that number peaked at 8,185 in 2017, then fell to 6,717 by 2023 — a 18% drop from peak
• The APP-to-physician ratio hit its high of 0.0301 in 2017 and declined to 0.0259 by 2023, nearly back to 2013 levels
• NPs and PAs billed 94.8 million services under CPT 99213 (standard office visit) — but received $9.83 less per service than MDs billing the same code
• Alaska leads all states with non-physicians delivering 14.52% of Medicare Part B services; the national picture is far more modest
• In nursing facility care (99309), NPs and PAs actually outbilled physicians — 37.4 million services vs. 18 million — yet still received $11.50 less per service

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The APP Headcount Peaked in 2017 and Has Been Falling Since

The narrative of an unstoppable APP surge in Medicare doesn't hold up against the raw counts. The number of unique NPs, PAs, and CRNAs billing Medicare grew steadily from 2013 to 2017, then reversed course sharply — falling from 8,185 to 6,717 over six years. That's a net decline of 1,468 providers, or roughly 18% from peak.

Physician counts followed a similar arc, peaking at 277,738 in 2019 before declining to 259,020 by 2023. But the APP decline started two years earlier and has been proportionally steeper. The APP-to-physician ratio in 2023 (0.0259) is essentially identical to what it was in 2014 (0.0287) — a decade of workforce expansion, erased.

The 2020 dip is visible in both groups — COVID-19's disruption to Medicare billing is well-documented — but physicians partially recovered while APPs did not.

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NPs and PAs Dominate Nursing Facilities but Get Paid Less Everywhere

Where APPs do show genuine volume dominance is in post-acute and nursing facility care. For CPT 99309 (subsequent nursing facility visit, ~25 minutes), NPs and PAs billed 37.4 million services — more than double the 18 million billed by MDs. For CPT 99308 (15-minute nursing facility visit), the gap is narrower but APPs still lead: 37 million vs. 24.3 million services.

Yet across every high-volume evaluation and management code in the data, MDs receive more per service. The gap ranges from $8.45 (CPT 99308) to $17.13 (a 99214 variant billed by time). On the single highest-volume code — CPT 99213 — MDs collected $49.46 per service vs. $39.63 for NPs and PAs, a 20% premium. That differential is structural: Medicare reimburses APPs at 85% of the physician fee schedule for most services.

The payment gap nearly disappears for drug injection codes. For denosumab (J0897), NPs and PAs actually averaged $1.22 more per unit than MDs ($15.62 vs. $14.40). For testosterone cypionate (J1071) and ferric carboxymaltose (J1439), the per-unit payments are statistically identical. The 85% rule applies to professional services, not drug reimbursement — and that distinction shows clearly in the data.

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Rural and Low-Density States Rely Disproportionately on Non-Physicians

The geographic distribution of APP billing is not random. Alaska (14.52%), Idaho (14.36%), Mississippi (13.31%), North Dakota (12.36%), and Utah (12.29%) top the state rankings for non-physician share of Medicare Part B services. Four of the top five are states with large rural or frontier populations and well-documented physician shortages.

Mississippi's position is notable: it ranks third nationally despite being a high-poverty, high-disease-burden state — not a wealthy urban market where APPs might be expanding into concierge or specialty niches. The bottom of the top-20 list includes Kansas (10.46%), North Carolina (10.24%), and Oregon (8.80%) — a mix of rural-heavy and mid-size states.

No large coastal metro-dominated state appears in the top 20. California, New York, Florida, and Texas — which together account for a massive share of total Medicare volume — are absent, consistent with those states having denser physician workforces relative to their Medicare populations.

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Open Questions

1. If the number of APPs billing Medicare has been declining since 2017, are these providers leaving Medicare entirely, shifting to commercial payers, or exiting the workforce — and does the answer differ by credential type (NP vs. PA vs. CRNA)?

2. NPs and PAs billed more nursing facility visits than MDs in aggregate — does that volume advantage translate into measurable differences in patient outcomes or readmission rates for Medicare beneficiaries in long-term care?

3. States like Mississippi and Alaska show APP shares above 13% — are those states' Medicare beneficiaries receiving a systematically different mix of services, or are APPs in those markets billing the same E&M-heavy codes as physicians elsewhere?