Comparing Australia’s biggest health funds: complaints, out-of-pocket costs and discounts

Australia’s private health insurance market can look crowded on paper. There are more than 40 insurers, yet most people can name only a handful. That familiarity is not accidental: around eight in 10 health insurance policies are held by the five biggest funds—Medibank, Bupa, HBF, HCF and NIB. Medibank and Bupa alone account for more than half of the market share between them.

Size, however, is not a guarantee of better value. Large funds can offer some strong options, but they also sell policies that represent poor value for some members. At the same time, smaller insurers—some with market share below 0.5%—can still be highly competitive and provide strong cover for relatively low premiums. The practical challenge for consumers is narrowing down choices in a way that focuses on what affects day-to-day value: complaints performance, out-of-pocket costs, and the discounts and rules that shape what you actually pay.

Why the “big five” dominate—and why that doesn’t settle the question

Concentration in the market means many households start their search with the best-known brands. That can be convenient, but it can also lead to assumptions—such as the idea that a bigger fund must automatically be better. In reality, the quality and value of cover still depends on the specific policy you choose and how it fits your circumstances.

Even within the biggest funds, there can be wide variation in value from one policy to another. This is why comparisons should not stop at the fund name. Looking at how funds perform on complaints and out-of-pocket costs can help you identify where the risks and trade-offs may sit, and then you can drill down to the policy level.

Complaints: how the big funds compare right now

One way to assess customer experience is to look at complaints handled by the Private Health Insurance Ombudsman. Based on complaints and serious disputes dealt with by the Ombudsman, each of the big five funds is currently rated Medium for complaints.

It is worth understanding what that rating means. Complaint performance is not measured by raw complaint counts alone. The approach takes the size of the fund into account, so a large fund is not automatically penalised just because it has more members and therefore more potential complaints. Ratings are grouped into Low, Medium and High. A Low rating is better than a High rating because it indicates fewer complaints and fewer serious disputes relative to the fund’s size.

At the moment, only a small set of insurers are rated Low: ACA, Hunter Health, Health Partners, Mildura and St Lukes. That doesn’t mean the big funds are “bad”—they sit in the middle band—but it does show that lower complaint performance is possible in the market and that fund size alone does not determine outcomes.

Out-of-pocket costs: understanding “gap” and why it matters

For many members, the most tangible cost is not the premium—it’s what they pay when they actually use their cover. Health funds vary in how well they protect members from out-of-pocket expenses for in-hospital treatments. This is often described as the “gap”: the amount a member pays out of their own pocket.

Funds can be rated for how likely they are to leave members out of pocket, using a “gap rating”—and the higher the gap rating, the better it is. These ratings are calculated on a state and territory basis and are based on the percentage of procedures in hospitals where members paid out-of-pocket costs (the gap payment).

In practice, gap outcomes are influenced by whether a fund has agreements with particular doctors and hospitals, and what those agreements cover. The gap rating takes into account the share of services where members paid either no gap or a known gap, compared with the state average.

Which big funds perform best on out-of-pocket costs?

Among the big five, Bupa and HBF stand out for lower out-of-pocket costs. They offer at least average gap protection in all states and above-average protection in one or more states. By contrast, the other large funds have below-average or worse gap protection in some states.

This state-by-state variation is important. A fund’s gap performance can look different depending on where you live, because the ratings are calculated separately for each state and territory. If you are comparing policies, it can be useful to ask not just “How does this fund perform on gap overall?” but “How does it perform where I live?”

Premium increases and prepayment: a timing lever available to everyone

All health funds allow members to prepay their annual premium before 1 April each year to avoid the premium increase—at least until the following year. This is a straightforward option that applies across funds and can help with budgeting if you are able to pay upfront.

For consumers who can manage annual prepayment, it can be worth checking whether your insurer treats prepayment as purely a timing benefit (avoiding the increase) or whether it also triggers an additional discount on certain policies.

Discounts: direct debit, annual prepay and partner arrangements

Discounts can materially change the price you pay, but they can also be easy to miss because they are not always automatically applied. Across the big five funds, several discount types appear in common:

• Annual prepayment before 1 April: available with all funds as a way to avoid that year’s premium increase until the following year.
• Direct deposit discounts: HBF and NIB offer a 4% discount for paying by direct deposit.
• Additional prepay discounts on some policies: HBF offers an additional 3.83% discount for prepaying the annual premium on some policies, creating a possible total discount of 7.84% when combined with the direct deposit discount.
• Partner/affiliate discounts: all big funds have discount agreements with organisations such as super funds, associations and clubs, or banks.

A practical takeaway is to ask your fund what discounts you qualify for. Many people may be eligible through an organisation they already belong to, without realising it. When comparing, it’s also worth confirming whether a discount is ongoing, limited to a period, or tied to a particular payment method.

Families, couples and “free kids”: how premiums typically work

A common feature of private health insurance pricing is that families pay the same premiums as couples, which effectively means children are insured for free under a family policy structure. This can make family cover attractive for households with children, but it also means the key cost question often shifts to the rules around older dependants—particularly adult children.

Adult children on family policies: what changed and what to check

In 2021, the government increased the age cap for adult children on their parents’ policy from 24 to 31. At the same time, the age limit was removed for dependants living with disability (NDIS participants).

However, these changes are not mandatory for private health funds. Insurers can set different age limits. One fund may allow young adults on family policies up to age 28, while another may allow them up to their 32nd birthday. This is a detail that can affect both eligibility and cost, so it’s worth confirming directly with the insurer you are considering.

Where adult children and full-time students can remain on a regular family policy for free up to age 31, there is usually an additional cost to keep older dependants and non-students covered. Depending on the insurer, this can add up to 30% to your premium.

There are also typically conditions attached. For example, children may need to be financially dependent, may not be married or in a de facto relationship, and there may be restrictions on how much income they can receive.

When it makes sense to keep adult children on your policy—and when it may not

If there is no extra cost, it often makes sense to keep adult children on the family policy. But once the insurer starts charging more, it becomes a decision about value and suitability. Adult children may not need the same level of cover as their parents, and their needs can be different at that stage of life.

For example, you may want a Silver, Silver Plus or Gold policy, while your adult children might be better suited to a Bronze policy, an extras-only policy, or potentially no health insurance at all. The right choice depends on their circumstances and what cover they actually use, but the key point is that “one family policy fits all” can become less true as children become adults.

Under-30 discounts: what’s available and how it works

For younger adults, pricing can be influenced by age-based discounts. Medibank, Bupa and NIB offer discounts to new customers who sign up before they turn 30.

The discount is structured as 2% off the premium for every year you’re below 30, up to a maximum of 10% for people aged 18–25. If you stay on that policy, you keep receiving the full discount until you turn 41.

These funds also allow you to keep the discount if you switch cover. They also allow you to carry over a discount if you currently hold one with another fund and switch to them. For consumers who are under 30 and comparing funds, this can be a meaningful factor—particularly if you expect to keep private health insurance for many years.

Profit status: nonprofit vs listed funds

Another difference between the big funds is their structure. HBF and HCF are the only large health funds that are nonprofit.

Medibank and NIB are listed on the stock exchange and pay dividends to shareholders. Bupa is for-profit, but it is part of the international Bupa Group that is nonprofit.

While structure does not automatically determine whether a policy is good value, it can be a point some consumers consider when weighing options—especially when comparing similar levels of cover and similar premium pricing.

How to use these comparisons when shopping for cover

Choosing a fund is rarely about a single metric. A practical approach is to treat the fund-level comparisons as a shortlist tool, then focus on policy details. Based on the information above, consumers comparing the big five can use a simple checklist:

• Complaints performance: all big five are currently rated Medium; if low complaints performance is a priority, note that some smaller funds are rated Low.
• Out-of-pocket (gap) protection: Bupa and HBF perform best overall for lower out-of-pocket costs, with at least average protection in all states and above average in one or more states.
• Discount eligibility: ask about direct deposit discounts, annual prepayment options, and partner/affiliate discounts you may qualify for through an organisation.
• Dependants and adult children rules: confirm age limits and conditions, and ask what premium impact applies to older dependants or non-students.
• Under-30 discounts: if you are under 30 and new to private health insurance, check whether Medibank, Bupa or NIB discounts apply and how long they last.

Because gap ratings are calculated on a state and territory basis, and because age limits and dependant conditions can vary by insurer, it is also worth verifying the details that apply to your location and household. Two people can buy “the same fund” and still have very different experiences depending on the policy, the state they live in, and whether they frequently use services that attract gap payments.

The bottom line

The dominance of Medibank, Bupa, HBF, HCF and NIB means many Australians naturally start their comparison with the big five. But size is not a shortcut to value. Complaint performance among the big five currently sits in the Medium band, while some smaller insurers achieve Low complaint ratings. On out-of-pocket costs, Bupa and HBF perform best overall by offering at least average gap protection in all states and above-average protection in one or more states, while other large funds are below average or worse in some states.

Discounts and eligibility rules can materially change what you pay. All funds allow annual prepayment before 1 April to avoid that year’s premium increase until the following year. HBF and NIB offer a 4% direct deposit discount, and HBF adds a further 3.83% annual prepay discount on some policies. All big funds also have partner discount arrangements, so it is worth asking what you qualify for. Finally, family policy rules—especially for adult children—can affect both eligibility and premiums, and the government’s 2021 changes are not mandatory for insurers, meaning age limits can differ.

For consumers using a “compare the market” approach, the most useful path is to combine fund-level signals (complaints and gap performance) with policy-level checks (discounts, dependants, and the cover level that matches each person’s needs). That is where the real differences in value tend to show up.