# ADP Retirement Services vs Vanguard: which do AI models recommend for 401(k) providers, October 2026

HR AI Recommendation Index, October 2026 Edition, 401(k) providers. Two of fourteen models named ADP Retirement Services first on the direct prompt; zero named Vanguard. Page: https://hr-ai-index.com/rewards/401k-providers/adp-retirement-services-vs-vanguard/

| | First-choice share | Rank | Negative rate | Labels | Models naming it |
|---|---|---|---|---|---|
| ADP Retirement Services | 16% | #3 of 12 | 12% | 41 | 14 of 14 |
| Vanguard | 5% | #7 of 12 | 4% | 46 | 14 of 14 |

## The direct prompt, model by model

- GPT-5.4 mini: adp retirement services first (first choices: ADP Retirement Services) (alternatives: Empower Retirement, Gusto, ShareBuilder 401k)
- Perplexity Sonar: adp retirement services first (first choices: ADP Retirement Services, Human Interest) (alternatives: Empower Retirement, Fidelity Advantage 401, John Hancock, Securian Financial)
- Claude Haiku 4.5: neither first, one named (first choices: Human Interest) (alternatives: Fidelity Investments, Principal, Vanguard)
- Gemini 3.5 Flash: neither first, one named (first choices: Human Interest) (alternatives: ADP Retirement Services, Fidelity Investments, Principal Financial Group)
- Grok 4.1 Fast: neither first, one named (first choices: Guideline, Human Interest) (alternatives: ADP Retirement Services, Charles Schwab, Fidelity Advantage 401, Principal, Vanguard)
- Mistral Small: neither first, one named (first choices: Fidelity Advantage 401) (alternatives: ADP Retirement Services, Empower Retirement)
- DeepSeek V4 Flash: neither first, one named (first choices: Fidelity Investments, Guideline, Human Interest) (alternatives: ADP Retirement Services, Empower Retirement, T. Rowe Price)
- Qwen 3.7 Flash: neither first, one named (first choices: Fidelity Investments, Guideline, Lighthouse Group) (alternatives: Charles Schwab, Vanguard)
- Kimi K2: neither first, one named (first choices: Fidelity Investments) (alternatives: ADP Retirement Services, Empower Retirement, T. Rowe Price, Vanguard)
- GLM 4.7 FlashX: neither first, one named (first choices: Human Interest) (alternatives: ADP Retirement Services, Fidelity Investments, Vanguard)
- Muse Glimmer 30B: neither first, one named (first choices: Empower Retirement, Fidelity Investments) (alternatives: ADP Retirement Services, Employee Fiduciary, Guideline, Human Interest, Nationwide, Vanguard)
- Llama 4 Maverick: neither named
- MiniMax M2.5: neither named (first choices: Human Interest) (alternatives: Empower Retirement, T. Rowe Price)
- GPT-6 Luna: neither named (first choices: ADP 401(k) Premier) (alternatives: Empower Retirement, Fidelity Workplace, Principal)

## What the models said about ADP Retirement Services

- "ADP's fee structures can sometimes be less transparent than modern digital-first providers ... their underlying fund options may feature slightly higher expense ratios." (Gemini 3.5 Flash, paraphrase prompt, soft negative)
- "Large, Bundled Payroll Providers Common Examples: *ADP Retirement Services and Paychex*... historically carry high administrative and recordkeeping costs" (Gemini 3.5 Flash, negative prompt, soft negative)
- "Concerns about "bundled" packages that may inflate total costs and obscure fee structures." (GLM 4.7 FlashX, negative prompt, soft negative)
- "This is widely considered the best option for very small teams because its pricing structure is designed to minimize costs" (Qwen 3.7 Flash, budget prompt, first choice)
- "Shortlist: ADP Enhanced (mid-sized focus), Fidelity, Vanguard, Schwab, or Human Interest/ForUsAll for tech-forward." (Grok 4.1 Fast, scale prompt, first choice)
- "ADP and Fidelity are often the top recommendations due to their flexibility, strong service, and tailored solutions" (Mistral Small, paraphrase prompt, first choice)

## What the models said about Vanguard

- "Vanguard is excellent for investing but not recommended for 401(k) administration" (GLM 4.7 FlashX, negative prompt, hard negative)
- "their 401(k) administration has drawn criticism... recommended using Vanguard funds through another provider instead" (DeepSeek V4 Flash, negative prompt, soft negative)
- "For Large/Midsize Businesses: Vanguard, Fidelity Investments, and Charles Schwab are renowned for offering excellent low-cost institutional index funds." (Gemini 3.5 Flash, negative prompt, first choice)
- "consider providers like Vanguard or Fidelity, which are known for lower fees and better investment options" (Mistral Small, negative prompt, first choice)
- "Want lowest-cost investing and a very large, established provider? Look at Vanguard." (GPT-5.4 mini, comparative prompt, first choice)

Share is the count of first choices across the direct, paraphrase, budget and scale prompts over all fourteen models, for a mid-market B2B company; rank is within the category. Comparisons are drawn for the top eight products in each category. Published under CC BY 4.0; the output is the models' output, and nothing here is a recommendation by the index.