Step-by-Step KiwiSaver Withdrawal Guide for Weight Loss Surgery (2025)

Using your KiwiSaver to fund weight loss surgery—such as a gastric sleeve, gastric bypass, or mini bypass is possible in New Zealand if you can prove medical necessity or financial hardship.

This guide walks you through every step of the process, from your first GP appointment to final approval.

It’s simple, clear, and specifically written for people applying for funding for bariatric surgery.

1. Confirm Whether Surgery Is Medically Necessary

KiwiSaver providers require evidence that:

• Your health is significantly affected by your weight

• Your GP believes surgery is medically necessary

• You have tried non-surgical treatments

• Delay could worsen your health

Common qualifying conditions:

• BMI ≥ 35

• Diabetes

• High blood pressure

• Sleep apnea

• Mobility issues

• Heart-related risks

If you are unsure, book a GP appointment and ask whether surgery could be considered medically essential for your long-term health outcomes.

2. Gather Medical Evidence Early

Providers expect to see documentation that supports your case.

This usually includes:

✔ GP Medical Letter

Essential for all applications.

The GP should mention:

• Your BMI

• Your diagnosis

• How your condition affects daily life

• Why non-surgical treatments haven’t worked

• Why surgery is recommended

• Expected benefits

(See our GP Letter Template for a ready-made example.)

✔ Specialist Notes (if available)

Not mandatory, but very helpful—especially for Simplicity and Booster.

✔ Health Records

These may include:

• Blood tests

• Sleep study results

• Diabetes metrics

• Weight history

The stronger the medical evidence, the faster the approval.

3. Get a Formal Cost Quote From a Bariatric Clinic

KiwiSaver providers will only consider the exact amount needed for surgery, not your full balance.

You must include:

• Type of surgery (sleeve, bypass, mini-bypass)

• Total cost

• Fees included (anaesthesia, theatre, hospital stay)

• Clinic details and GST number

• Payment deadline (if specified)

Most NZ clinics respond within 1–3 days.

4. Download Your KiwiSaver Provider’s Withdrawal Form

Each provider has its own required forms.

Most forms include:

• Medical withdrawal form

• Hardship form (if applying under hardship criteria)

• Statutory declaration

• Identity verification requirements

Here are links to the main NZ providers:

• Milford – medical withdrawal form

• Booster – medical withdrawal form

• Simplicity – hardship & medical forms

• AMP – early withdrawal forms

• ANZ – medical grounds withdrawal form

• Fisher Funds – medical withdrawal form

(Requirements vary, but the overall process is similar.)

5. Prepare Your Supporting Documents

Your application must be complete. Missing documents cause the majority of delays.

A complete application includes:

• GP letter

• Clinic cost estimate

• Photo ID

• Bank statements (3 months) — hardship only

• Income & expense summary — hardship only

• Any specialist notes

• Additional medical evidence

Tip: Combine all documents into a single PDF if possible to make your provider’s job easier.

6. Write a Short Personal Statement (Highly Recommended)

Not required, but highly effective.

A simple paragraph can explain:

• Why surgery is necessary

• How your condition affects your health

• Why you need KiwiSaver to fund the procedure

• That you have no alternative funding

Example:

“My weight is causing significant health issues, including hypertension and sleep apnea. Non-surgical treatments have not been effective. My GP considers surgery medically necessary. I am unable to afford the procedure without accessing my KiwiSaver.”

This helps humanise your application.

7. Submit the Application

Most providers accept applications via:

• Email

• Provider portal upload

• In-person drop-off (rarely needed)

Be sure to follow the provider’s checklist carefully.

Double-check before sending:

✔ GP letter included

✔ Full clinic quote attached

✔ ID verified

✔ Statutory declarations signed

✔ Hardship evidence included (if applicable)

8. Processing Time: What to Expect

Typical processing times in New Zealand:

• Medical-only applications: 5–15 working days

• Financial hardship applications: 10–20 working days

Delays happen when:

• GP letter is too short

• Documents are missing

• Expenses/income breakdown isn’t clear

• Provider asks for additional medical evidence

Follow-up is normal.

Providers may request:

• Additional medical clarification

• Updated bank statements

• More detailed personal statement

• Proof that loans/insurance aren’t viable

9. How Providers Make Their Decision

KiwiSaver providers evaluate:

✔ Medical necessity

If your GP strongly supports the surgery, approval odds improve significantly.

✔ Evidence of hardship (if relevant)

They check whether surgery is affordable without KiwiSaver.

✔ Supporting documents

More complete = faster decision.

✔ Alternative funding sources

Providers must legally assess whether you could pay another way.

✔ Surgery cost transparency

Your clinic quote must be clear and final.

10. What Happens After Approval?

Once approved:

• Funds are transferred directly to the clinic

• You will receive an approval letter

• The surgery can be scheduled or confirmed

• Your KiwiSaver account will update its balance

Approval letters usually state:

• Amount released

• Legal basis (medical withdrawal or hardship)

• Any conditions

• Timeline for payment

11. If Your Application Is Declined

This is more common when:

• Medical evidence was incomplete

• GP letter lacked detail

• Hardship wasn’t demonstrated

• Provider believed alternative funding was possible

What you can do:

• Strengthen your GP letter

• Add missing documents

• Provide clearer hardship evidence

• Request a reconsideration

• Switch to a different provider (not immediate, but possible long-term)

We have a full guide here:

KiwiSaver Hardship Withdrawal for Weight Loss Surgery →

12. Summary

Applying for a KiwiSaver withdrawal to fund bariatric surgery is absolutely possible in 2025 if:

• Your GP confirms surgery is medically necessary

• Your supporting documents are complete

• Your financial situation justifies withdrawal (hardship route)

• Your application is clearly presented

A well-prepared application dramatically increases your chances of fast approval.

Want personalised help checking your eligibility?