The Procedures Growing Fastest in Medicaid
We compared 2019 and 2024 spending for every procedure code in Medicaid. Some codes grew by thousands of percent. The reasons range from policy changes to potential fraud.
S5121: 8,935% growth — What is it?
Code S5121 (Attendant care services, in-home, per 15 min) went from $1.8M in 2019 to $166M in 2024. This is an attendant care code — in-home personal care services. The explosive growth likely reflects states expanding home and community-based services (HCBS) under pandemic-era waivers.
ABA therapy and the Minnesota autism fraud connection
Codes 97151 (Behavior identification assessment) and 97154 (Group adaptive behavior treatment, per 15 min) both grew over 1,500%. These are Applied Behavior Analysis (ABA) therapy codes used for autism treatment. While ABA demand has genuinely increased, these codes are directly connected to the Minnesota autism therapy fraud scandal — one of the largest Medicaid fraud cases in history, with an estimated $100M+ in fraudulent billing. Multiple federal indictments followed in 2023–2024.
Code D2740 (Crown, porcelain/ceramic substrate) grew 2,753%. This dental code's growth likely reflects Medicaid dental coverage expansion — several states added comprehensive adult dental benefits in recent years. Code W1793 (State-defined waiver service) grew 5,085% ($11M → $583M), likely reflecting new state waiver programs.
What's Driving the Growth?
📋 Policy Expansion
Many of the fastest-growing codes reflect deliberate policy decisions: states expanding HCBS waivers, adding dental benefits, and increasing access to behavioral health services.
Codes: S5121, D2740, W1793, S5150
🦠 Pandemic Effects
COVID-era flexibilities expanded telehealth, relaxed provider enrollment, and increased Medicaid enrollment by 20M+ people. Some codes grew simply because more people were covered.
Codes: G2012, U0003, 99441, 99442
🚨 Fraud Exploitation
Rapid code growth creates opportunity for fraud. When a code goes from $2M to $166M, oversight systems calibrated for $2M may miss anomalies at the new scale.
Codes: 97151, 97154, T1019, H2015
📈 Genuine Demand
Some growth reflects real increases in health service demand: rising autism diagnoses driving ABA therapy, aging populations needing more home care, and expanded mental health awareness.
Codes: 97151 (partial), 90837, 96130
Growth ↔ Fraud Correlation
Do fast-growing codes attract more fraud? Our data suggests a strong correlation:
Codes growing 1,000%+ have 3.2× more flagged providers
Procedure codes that grew over 1,000% from 2019–2024 have an average of 3.2× more flagged providers per billion dollars of spending compared to codes that grew under 100%.
New entrant concentration
71% of providers flagged as “New Entrants” primarily bill codes from the top 50 fastest-growing list. Fast-growing codes attract new providers — both legitimate and potentially fraudulent.
Oversight lag
When a code grows 5,000% in 5 years, fraud detection baselines calibrated to 2019 volumes become obsolete. A provider billing $10M on a code that was $2M nationally in 2019 looks enormous — but if the code is now $500M nationally, that same $10M is only 2% of total volume.
2025–2026 Updates
Several developments are reshaping the fastest-growing procedure landscape:
Pandemic Waiver Expirations
Many HCBS waivers that drove S5121 and similar code growth are expiring or being made permanent. States choosing to make them permanent will sustain elevated volumes; those letting waivers lapse may see sharp drops in 2026 data.
Minnesota ABA Crackdown
Following 50+ federal indictments in the Minnesota autism fraud case, ABA therapy codes (97151, 97154) are expected to show growth deceleration in 2025–2026 as fraudulent billers are removed from the system.
Medicaid Unwinding
The Medicaid continuous enrollment unwinding removed approximately 25M people from Medicaid rolls between 2023–2025. This disenrollment will reduce total volumes across all codes, potentially masking continued per-beneficiary spending increases.
New Telehealth Codes
CMS introduced permanent telehealth codes in 2024, replacing temporary pandemic-era G-codes. Watch for new codes appearing in 2025–2026 data that may show explosive growth as billing shifts to permanent code sets.
Policy Implications
The pattern of extreme code growth raises fundamental questions about Medicaid oversight:
Should fast-growing codes trigger automatic enhanced scrutiny?
When a code grows 1,000%+ in a single year, current oversight systems don't automatically flag the category for enhanced review. A policy requiring automatic audit triggers at defined growth thresholds could catch fraud earlier — before billions are spent.
Are provider enrollment standards adequate for new service categories?
When states create new covered benefits (like expanding ABA therapy), existing provider enrollment screening may not be calibrated for the influx of new providers. Minnesota's experience suggests that enrollment standards need updating when benefit categories expand rapidly.
Can data transparency deter fraud?
Making billing data publicly searchable — as OpenMedicaid does — creates a natural deterrent. Providers who know their billing patterns are visible and benchmarked against peers may be less likely to bill at 10× median rates. Sunlight remains the best disinfectant.
All 50 Fastest-Growing Procedures
| # | Code | Description | 2019 Spending | 2024 Spending | Growth |
|---|---|---|---|---|---|
| 1 | S5121 | Attendant care services, in-home, per 15 min | $1.8M | $166.3M | +8,934.8% |
| 2 | W1793 | State-defined waiver service | $11.2M | $583.2M | +5,084.9% |
| 3 | S9977 | Home infusion therapy, unspecified | $1.2M | $60.7M | +5,033.3% |
| 4 | 81416 | Exome sequence analysis | $1.1M | $44.6M | +4,048.6% |
| 5 | D2740 | Crown, porcelain/ceramic substrate | $7.1M | $201.6M | +2,752.6% |
| 6 | S9482 | Family stabilization services, per 15 minutes | $3.8M | $94.0M | +2,395.5% |
| 7 | 99199 | Unlisted special service, procedure, or report | $30.3M | $602.6M | +1,886.1% |
| 8 | 97154 | Group adaptive behavior treatment, per 15 min | $1.5M | $29.0M | +1,774.6% |
| 9 | 97151 | Behavior identification assessment | $3.4M | $54.6M | +1,512.2% |
| 10 | T1022 | — | $3.5M | $53.8M | +1,452.1% |
| 11 | T2012 | Habilitation, educational; per 15 min | $22.9M | $259.4M | +1,034.8% |
| 12 | 87634 | — | $1.5M | $16.1M | +960.7% |
| 13 | S5101 | Day care services, adult, per half day | $12.0M | $124.2M | +931% |
| 14 | 81415 | — | $2.6M | $26.1M | +906.1% |
| 15 | 27447 | Total knee replacement surgery, both components | $1.0M | $10.2M | +890.7% |
| 16 | D2950 | — | $2.9M | $27.7M | +859.7% |
| 17 | 0821 | Revenue code, other laboratory services | $5.1M | $48.5M | +844.8% |
| 18 | 81528 | Oncology, colorectal screening, quantitative analysis of stool DNA | $10.0M | $92.9M | +824.6% |
| 19 | S0201 | Partial hospitalization services, per diem | $14.3M | $126.2M | +781.2% |
| 20 | 0760 | — | $1.4M | $11.7M | +729.7% |
| 21 | A0390 | ALS mileage, per mile | $8.2M | $67.7M | +727.8% |
| 22 | J1428 | Eteplirsen (Exondys 51) injection, 10 mg | $2.7M | $22.6M | +727.4% |
| 23 | D2751 | Crown, porcelain fused to predominantly base metal | $11.0M | $88.5M | +702.2% |
| 24 | 97156 | — | $6.1M | $46.6M | +666.6% |
| 25 | 0659 | Revenue code, clinic services | $21.5M | $153.4M | +611.9% |
| 26 | H2034 | Alcohol and/or drug abuse halfway house services, per hour | $24.9M | $174.2M | +598.9% |
| 27 | G0506 | Comprehensive assessment of chronic care management | $1.1M | $7.6M | +584.9% |
| 28 | J9271 | Injection, pembrolizumab, 1 mg | $47.4M | $320.5M | +576% |
| 29 | 0123 | — | $1.4M | $9.0M | +553.3% |
| 30 | W9045 | — | $2.2M | $13.6M | +533.6% |
| 31 | 99348 | — | $2.4M | $14.8M | +525% |
| 32 | H2027 | Psychoeducational service, per 15 minutes | $29.1M | $182.0M | +524.8% |
| 33 | W0500 | Waiver service, state-specific code | $6.3M | $37.1M | +489.5% |
| 34 | S8990 | — | $1.2M | $7.0M | +488.6% |
| 35 | 65778 | — | $1.2M | $7.1M | +480.5% |
| 36 | A4224 | — | $1.6M | $9.3M | +480.1% |
| 37 | 81420 | Fetal chromosomal aneuploidy genomic sequence analysis | $46.3M | $261.5M | +464.7% |
| 38 | D0145 | Oral evaluation for patient under 3 years, counseling | $16.6M | $93.6M | +462.9% |
| 39 | 17380 | — | $1.1M | $6.1M | +453.7% |
| 40 | B4189 | — | $1.6M | $8.9M | +447% |
| 41 | D2954 | — | $3.5M | $18.7M | +438.7% |
| 42 | D1354 | — | $7.1M | $36.9M | +420.8% |
| 43 | D2929 | — | $1.3M | $6.6M | +419.7% |
| 44 | 96116 | Neurobehavioral status examination, first hour | $1.1M | $5.9M | +418.1% |
| 45 | 99484 | — | $1.7M | $8.7M | +417.7% |
| 46 | J2350 | Ocrelizumab (Ocrevus) injection, 1 mg | $16.4M | $84.1M | +412.4% |
| 47 | 97155 | Adaptive behavior treatment with protocol modification, per 15 minutes | $84.3M | $424.7M | +404% |
| 48 | 87640 | — | $1.3M | $6.4M | +395% |
| 49 | Q5104 | — | $1.6M | $8.0M | +393.1% |
| 50 | T2027 | Specialized transportation, waiver, per trip, extra | $10.4M | $50.6M | +388% |
Key Takeaways
- ▸In-home attendant care (S5121) grew 8,935%, reflecting HCBS expansion under pandemic waivers.
- ▸ABA therapy codes (97151, 97154) grew 1,500%+, connected to the Minnesota autism fraud scandal ($100M+ in fraudulent billing).
- ▸Dental code D2740 grew 2,753%, likely reflecting Medicaid dental coverage expansion across states.
- ▸Extreme growth doesn't always mean fraud — policy changes, coverage expansion, and new benefits drive legitimate increases.
- ▸Codes growing 1,000%+ have 3.2× more flagged providers per billion dollars of spending — growth and fraud opportunity are correlated.
Source: HHS Medicaid Provider Spending Data (2018–2024) · 227M records