Hammock vs Flex: Consumer HSA vs B2B Payment Infrastructure

Hammock and Flex are not competitors — they serve entirely different markets. Hammock is a consumer HSA with built-in Letters of Medical Necessity for individuals. Flex is B2B payment infrastructure that helps employers and benefits platforms manage pre-tax health and wellness spending. Understanding the difference helps you pick the right tool for your situation.

What Hammock Does

Hammock is a Health Savings Account designed for individuals who want to maximize their HSA for wellness expenses. The core offering:

HSA debit card that works like any other HSA
Unlimited Letters of Medical Necessity (LMNs) included
FSA support for those with Flexible Spending Accounts
Provider network that evaluates your conditions and issues LMNs — often without in-person visits

The result: expenses like gym memberships, supplements, massage, standing desks, and mental health apps become tax-free HSA purchases when you have a qualifying medical condition.

Who it's for: Individuals with an HDHP who want to use their HSA for wellness expenses that normally require extra documentation.

What Flex Does

Flex (formerly Flex Benefits) is enterprise infrastructure. They provide APIs and platforms that help:

Employers administer pre-tax benefit programs (HSA, FSA, HRA, commuter benefits)
Benefits platforms integrate pre-tax spending into their products
Payroll providers manage benefit deductions and compliance

Flex doesn't give you an HSA card or help you get an LMN. They help _companies_ build and manage benefits programs at scale.

Who it's for: Employers, HR platforms, and benefits administrators who need infrastructure to run pre-tax benefit programs.

The Key Differences

You're an Individual Wanting to Use Your HSA for Wellness

Choose Hammock. Flex doesn't serve you directly — they work with your employer behind the scenes. Hammock gives you the HSA card and LMNs you need to make wellness expenses tax-free.

You're an Employer Building a Benefits Program

Look at Flex (among other benefits administrators). You might also recommend Hammock to your employees as their individual HSA provider, but the infrastructure decision is separate.

You're a Benefits Platform Adding Pre-Tax Features

Flex's APIs might help you integrate pre-tax spending into your product. Hammock isn't competing for your business — they're serving the end consumers.

How They Could Work Together

Here's an interesting scenario: an employer could use Flex's infrastructure to administer their benefits program while their employees individually choose Hammock as their HSA provider. The two aren't mutually exclusive — they operate at different layers of the benefits stack.

Think of it like this:

Flex = the plumbing (infrastructure for employers)
Hammock = the faucet (the product individuals interact with)

The LMN Advantage

The biggest differentiator for Hammock isn't the HSA itself — most HSAs work the same way. It's the unlimited LMNs.

Traditional HSAs leave you to figure out Letters of Medical Necessity on your own. That means scheduling doctor appointments, explaining what an LMN is, and hoping your provider cooperates. Most people just give up and pay for wellness expenses with after-tax dollars.

Hammock eliminates this friction entirely. The LMN process is built into the product:

You identify a wellness expense you want to cover (gym, supplements, massage, etc.)

Hammock's provider network evaluates whether you have a qualifying condition

If you qualify, they issue an LMN

You pay with your Hammock HSA card — tax-free

No separate appointments. No explaining HSA rules to your doctor. No paperwork.

What Can You Actually Cover With Hammock?

With the right qualifying conditions and LMNs, Hammock HSA users can potentially cover:

Gym memberships and fitness classes
Supplements and vitamins
Massage therapy
Standing desks and ergonomic equipment
Fitness equipment (Peloton, weights, etc.)
Mental health apps (Headspace, Calm)
Sleep products (weighted blankets, white noise machines)
Health monitoring devices (Whoop, Oura Ring)
Nutrition and meal planning services

All tax-free, all from your HSA. The LMN is what unlocks each category.

FAQ

Is Hammock a Flex competitor?

No. Hammock is a consumer-facing HSA with built-in LMN services. Flex is B2B infrastructure for employers and benefits platforms. They serve different customers at different layers.

Can I have both a Flex-administered HSA and a Hammock HSA?

You can only have one HSA that receives contributions at a time, but you can transfer your HSA balance to a new provider. If your employer uses Flex's infrastructure and you want Hammock's LMN benefits, you could potentially roll over your HSA to Hammock or maintain both accounts (contributions to one, Hammock for LMN-backed spending).

Does Flex offer Letters of Medical Necessity?

No. Flex provides payment infrastructure and benefits administration. LMNs are a clinical service — Hammock partners with licensed providers to offer them as part of the HSA experience.

How much does Hammock cost compared to Flex?

They're not comparable. Hammock charges individuals an annual fee for the HSA membership with unlimited LMNs. Flex charges employers and platforms for their infrastructure services — pricing varies based on scale and features.

Can my employer sign up for Hammock on my behalf?

Hammock is designed for individual enrollment. Your employer can recommend it, but you sign up and manage your own HSA. This is different from employer-administered HSAs through providers like Flex.

Bottom Line

If you're an individual looking to maximize your HSA for wellness and fitness expenses, Hammock is built for you. If you're an employer or platform looking for benefits infrastructure, Flex operates in that space. They solve different problems for different people — and understanding that saves you from comparing apples to oranges.

Ready to start using your HSA for wellness? Hammock includes unlimited Letters of Medical Necessity — so your gym, supplements, and massage are all tax-free.