How Future Medical Costs Are Proven in a Washington Injury Case

If an injury may require treatment months or years from now, the cost should not be treated as a number someone can simply add to a claim. Under Washington law, the evidence must first show that injury-related care will be needed with reasonable probability or reasonable certainty. The record then needs a reasonable basis for identifying and pricing that care.

For a claimant in Vancouver or elsewhere in Clark County, that usually means addressing several connected but distinct questions:

Why will future care probably be needed?
Is that need caused by the injury at issue?
What treatment, service, equipment, medication, or assistance is anticipated?
How often will it be needed, and for how long?
What is a reasonable cost for the supported care?
Is each opinion offered by someone qualified to give that particular opinion, and does it have an adequate foundation?
If present value is at issue, what evidence supports the calculation?

These are statewide Washington principles. Clark County does not apply a different substantive standard.

The Short Answer: A Projection Must Show Both Future Need and a Reasonable Amount

A future-medical-cost claim has two basic stages of proof.

First, the evidence must establish that a particular future loss probably exists: the injury will require future medical care. Second, the evidence must provide a reasonable basis for estimating the amount of that loss.

That order matters. Washington decisions distinguish proof that future care will probably be needed from proof of what it will cost. Once the existence of the loss is established, exact mathematical precision is not necessarily required if the evidence allows a reasonable estimate. But a flexible approach to calculating an amount cannot supply missing proof that the treatment itself will probably be needed because of the injury. Conjecture is not enough.

In practical terms, even a carefully calculated total may be poorly supported if it begins with uncertain treatment assumptions. A sound projection starts with the medical need and causal connection, then works through the details and price.

Future Medical Expenses Are Different From Past Bills and Noneconomic Harm

Future medical expenses are the economic value of care that has not yet been incurred. They are different from:

expenses associated with treatment already received;
future pain, inconvenience, or loss of enjoyment of life;
and future loss of earning capacity.

Those categories may arise from the same injury, but they answer different questions and require different evidence. For example, existing invoices may matter to both past and future cost questions, but a bill for completed care does not by itself prove that the same care will be required again.

Readers trying to understand completed treatment expenses can review past medical bills and amounts paid in Washington claims. Future pain and other noneconomic effects are addressed separately in this explanation of Washington pain-and-suffering damages.

Start With Proof That Future Care Will Probably Be Needed

Washington permits recovery for future medical attention that a claimant is reasonably certain to incur because of the injury. The Washington Pattern Jury Instructions similarly describe this element as the reasonable value of necessary care, treatment, and services that, with reasonable probability, will be required in the future. The pattern instructions are nonbinding committee guidance, not independently controlling law, and the committee note says the element should be included only when the evidence justifies it.

The threshold question is therefore not whether a treatment could occur or might be helpful someday. It is whether the evidence supports the conclusion that future care is reasonably probable or reasonably certain.

Washington does not require proof of a permanent injury in every future-medical-expense claim. Evidence may support care for a defined period after trial even if it does not establish lifelong impairment. The probable nature and duration of that care still need support.

Reasonable probability is not absolute certainty

Washington’s standard does not demand certainty beyond all doubt. At the same time, a mere possibility is not enough. A statement that treatment is conceivable, may be needed, or cannot be ruled out may leave an important gap between possibility and reasonable probability.

The evidence should communicate why the anticipated care crosses that line. Depending on the issue and the record, that may involve prognosis, clinical findings, the expected course of the condition, response to earlier treatment, or another adequately supported basis. The precise foundation will vary with the claimed injury and care.

Ongoing symptoms and treatment history may matter, but the record controls

Past treatment, ongoing impairment, and evidence that continuing treatment is essential or reasonably probable can support an inference of future need in appropriate circumstances. In Erdman v. Lower Yakima Valley Lodge, for example, the court considered a developed record that included severe continuing impairment, substantial prior medical and rehabilitation efforts, and evidence of continuing care and assistance needs.

That does not create a rule that ongoing symptoms or treatment history automatically establish future expenses. The conclusion remains tied to the whole record. History can help explain the future, but it does not eliminate the need to show what care will probably be required.

Connect the Future Care to the Injury at Issue

A treatment can be medically reasonable in general without being a future expense caused by the injury involved in the claim. Causation is therefore a separate part of the analysis.

In Leak v. U.S. Rubber Co., the Washington Court of Appeals explained that medically complex causation must be established with reasonable certainty. Possibility, conjecture, or the fact that one event followed another is not necessarily enough. The evidence must connect the anticipated need to the injury at issue rather than leave the relationship assumed.

The materials supporting the claim should identify the basis for attributing the anticipated care to the compensable injury rather than treating that connection as assumed.

Complex causation may call for qualified medical opinion

When causation is not clearly disclosed by circumstantial evidence, Leak says medical testimony is necessary and must reach the level of “probably” or “more likely than not.” That does not mean expert testimony is invariably required for every issue in every future-care claim. Published Washington authority also recognizes that a sufficiently developed record may permit an inference from the circumstances.

The careful answer is issue-specific: medically complex causation often requires a qualified medical opinion, while the need for opinion evidence on other points depends on what the record already establishes and whether the subject is within ordinary experience.

Identify the Specific Treatment, Service, or Support

A general statement that someone will need “future care” leaves unanswered what is actually being claimed. A useful projection identifies each material item—such as an appointment, therapy, medication, procedure, equipment, or assistance—and the provider recommendation or other competent support behind it.

Direct testimony can establish probable future care and cost when the witness is qualified and the opinion is adequately supported. In Stevens v. Gordon, for example, a treating physician testified that the claimant would more probably than not require future care and gave testimony about lifetime cost. The claimant also testified that she intended to seek further care as needed. The court’s sufficiency determination rested on that particular record; it is not a shortcut for other cases.

The broader point is that a bottom-line total should be traceable to supported care items. If the file identifies a possible procedure but contains no opinion that the procedure will probably be needed, pricing it does not resolve the missing need evidence.

A price list cannot originate a medical recommendation

Determining that a service is medically necessary and determining its price are different functions. A qualified cost witness or life-care planner may be able to organize supported provider recommendations and price items within that witness’s expertise. An independent opinion that a treatment is medically necessary, however, requires its own issue-specific qualification under Evidence Rule 702 and an adequate foundation under Evidence Rule 703.

Published Washington authority located for this article does not create a categorical rule that life-care planners are required, prohibited, or automatically qualified to offer medical-necessity opinions. The proper inquiry concerns the particular witness, the particular opinion, that witness’s qualifications, and the opinion’s factual foundation. A witness’s ability to research prices does not automatically establish an ability to diagnose an injury, determine causation, or originate a treatment recommendation.

Support How Often Care Is Expected and How Long It May Continue

Identifying a supported treatment is only part of the projection. The total also depends on frequency and duration.

For each significant item, the record may need to address questions such as:

When is the care expected to begin?
How many visits, treatments, or units are anticipated?
At what interval will the care or replacement occur?
For what period is it expected to continue?
What provider recommendation or other competent evidence supports those assumptions?

A treatment may be reasonably probable while a proposed number of sessions or years remains unsupported. Because frequency multiplied by duration often drives the total, an unexplained assumption can materially change the projection.

Future care does not have to be lifelong

Future care can be limited in time. Leak recognizes that a claimant need not prove permanent injury when the evidence supports reasonably certain treatment for a defined period.

The reverse is also important: a projection should not use a lifetime duration simply because the effects have lasted until now. “Lifetime” is a factual assumption that needs support, just like treatment type and frequency.

Build a Reasonable Cost Estimate for the Supported Care

Pricing comes after the evidence supports need, causation, the care item, frequency, and duration. Washington allows reasonable estimation once the existence of a loss has been established; it does not necessarily demand mathematical exactness. But the estimate must still rest on evidence rather than conjecture.

A cost presentation should make its components understandable. Depending on the item and available evidence, that may include a unit price, a supported quantity or visit count, an expected interval, and a supported treatment period. Moore v. Smith, a general damages case rather than a future-medical-expense case, states the broader Washington principle that the amount may be assessed more liberally after liability for the loss is established, so long as the record supplies a reasonable basis for estimation.

What medical records and bills can—and cannot—show

Under Patterson v. Horton, medical records and bills may help prove the cost of future treatment without the additional reasonableness-and-necessity showing required when those documents are offered to prove past medical expenses.

That is a limited point. Existing records or bills may provide cost information, but they do not independently establish:

that the future care is caused by the injury;
that it will probably be needed;
which treatment or service will occur;
how often it will occur; or
how long it will continue.

A past charge may therefore be one part of a cost foundation, not a substitute for the rest of the future-care evidence.

Check every assumption behind the total

Before relying on a projected total, it can help to trace each line item through a simple chain:

Recommendation: Who supports the treatment or service, and what exactly was recommended?
Causation: What connects that recommendation to the injury at issue?
Probability: What supports the conclusion that the item will probably be needed?
Frequency: How many times, or at what interval, is it expected?
Duration: For how long is it expected to continue?
Unit price: Where did the cost figure come from?
Total: Does the arithmetic follow the supported assumptions?

The admissibility of a pricing database, provider quotation, underlying recommendation, or other source depends on the particular qualifications, disclosures, reasonable-reliance foundation, and trial-court gatekeeping. Evidence Rule 703 can permit an expert to rely on some information that would not itself be admissible, but it does not automatically admit that information for its truth or make an unsupported assumption reliable.

Match Each Opinion to the Witness’s Qualifications and Foundation

The important question is not simply, “Was an expert involved?” It is whether each witness is qualified to give the specific opinion offered, whether that opinion will assist the factfinder, and whether it stays within an adequately supported scope.

Evidence Rule 702 looks to knowledge, skill, experience, training, or education. Qualification is opinion-specific. One witness may be qualified to discuss diagnosis or prognosis, another to price a supported service, and another to address an economic calculation. A professional label alone does not establish every link in the proof.

Washington trial courts also examine whether an opinion has an adequate foundation instead of resting on speculation, conjecture, or misleading assumptions. In Johnston-Forbes v. Matsunaga, the Washington Supreme Court treated qualification, helpfulness, and adequate scope as important parts of that inquiry. A lack of personal examination may affect the weight of an otherwise well-founded opinion rather than automatically make it inadmissible, but the result remains dependent on the particular opinion and record.

Treating providers and retained experts are assessed opinion by opinion

A treating provider may have firsthand knowledge that supports an opinion about causation, prognosis, future-care necessity, or cost. That provider may offer such an opinion when qualified for the specific subject and when the opinion has an adequate foundation.

Treating status is not an automatic qualification, however, and retained status is not the legal test under ER 702. Both treating and retained witnesses remain subject to requirements concerning qualification, relevance, scope, foundation, and applicable procedural disclosure.

An ARNP’s causation testimony requires issue-specific qualification

In Frausto v. Yakima HMA, LLC, the Washington Supreme Court rejected a categorical rule barring advanced registered nurse practitioners from giving medical-causation testimony in a medical-negligence case. It held that an ARNP may testify on causation if the trial court determines that the witness satisfies ER 702 for the particular issue, and it reversed and remanded for further proceedings. The decision did not eliminate all profession-specific limits; footnote 1 preserves the boundary for testimony about a physician’s standard of care.

That case supports an issue-specific qualification analysis. It does not automatically qualify a nonphysician planner—or any other professional—to give an independent medical-necessity opinion. Nor does it create a categorical exclusion. The witness’s demonstrated expertise must fit the opinion being offered.

ER 703 informs the opinion’s foundation but does not expand expertise

Evidence Rule 703 allows an expert to base an opinion on facts or data perceived by or made known to the expert, including otherwise inadmissible information of a type reasonably relied on by experts in the field.

The rule has limits. It does not:

expand the subjects on which a witness is qualified to opine;
turn an unsupported assumption into a reliable one; or
automatically admit the underlying information for its truth.

For a future-care projection, that means reliance on provider recommendations, records, quotations, or other data still has to fit the expert’s field and the opinion’s foundation.

Address the Present Cash Value of Future Economic Losses

WPI 34.02 states that future economic awards are measured by present cash value: the amount now that, invested at a reasonable return, will fund supported expenses when they are due. That measure is distinct from simply adding up expenses expected in future years.

These pattern instructions are nonbinding committee guidance. Giving the present-value instruction requires supporting evidence of an appropriate rate and calculation guidance; this evidentiary requirement does not mean the claimant simply chooses whether to discount. No single calculation method is mandatory, and supported inflation assumptions may matter. Noneconomic damages are not reduced to present cash value under that guidance.

A present-value instruction needs an evidentiary basis

In Mendelsohn v. Anderson and Snow v. Whitney-Fidalgo Seafoods, Inc., the Washington Court of Appeals explained that a jury should not be instructed to discount future economic damages without evidence supplying an appropriate interest rate and calculation guidance. A bare instruction without a proper rate or mathematical foundation can leave the jury to speculate.

Present-value analysis therefore adds another set of assumptions to examine. The rate, timing, duration, and calculation method need evidentiary support; they should not be silently embedded in a total.

Annuity evidence is one permissible method, not a purchase requirement

Cornejo v. State recognizes that qualified evidence about the cost of an annuity may be admitted as one way to establish the present cash value of future economic losses when it satisfies ER 702 and ER 703. That does not mean an annuity must be purchased or that annuity evidence is the only permissible method. The factfinder may evaluate the assumptions, including those involving interest and inflation.

A Practical Evidence Checklist for Vancouver and Clark County Claimants

Future-care evidence may develop as the medical picture develops. Without suggesting that every claimant must wait for a particular milestone, the following questions can help reveal whether a projection is complete enough to evaluate:

Need: Does the record explain why future care will probably be needed, rather than merely identifying a possibility?
Causation: Does it connect that care to the injury involved in the claim?
Specific care: Does it identify each material treatment, service, medication, equipment item, or form of assistance?
Frequency: Does it support the expected number of visits, units, or replacements?
Duration: Does it support a limited treatment period or, if claimed, a longer duration?
Price: Is there a reasonable source for the unit price and total cost?
Opinion source: Is each witness qualified for the particular opinion being offered?
Foundation: Can each significant assumption be traced to records, provider recommendations, data, or another adequately supported source?
Present value: If a present-value calculation is used, does evidence support the rate and method?

Preserve the medical records, provider recommendations, bills, quotations, and calculation assumptions supporting each projected item. Keeping those materials together can help distinguish documented support from an unexplained estimate; it does not guarantee admissibility or recovery.

An evolving prognosis is one reason Washington injury-claim timing can vary. The relevant point here is not that there is one correct time to resolve every claim, but that a future-care estimate is only as sound as the medical and cost information supporting it.

Frequently Asked Questions

Do I need a permanent injury to claim future medical expenses in Washington?

Not necessarily. Published Washington authority recognizes that future medical care may be supported for a defined period even without proof of permanent injury. The evidence still needs to establish with reasonable probability or certainty what care will be needed and for how long.

Does every future-medical-cost claim require expert testimony?

No universal rule in the sources reviewed for this article makes expert testimony mandatory for every future-care issue. A sufficiently developed record may support an inference in some circumstances. Medically complex causation and detailed projections, however, may require qualified opinion evidence. The answer depends on the issue and the record.

Can a treating provider testify about future care?

Potentially. A treating provider may offer an opinion about causation, prognosis, necessity, or cost when qualified for that specific subject and supported by an adequate foundation. Treating status neither automatically qualifies nor disqualifies the provider.

Is a life-care planner required to prove future medical costs?

The Washington sources reviewed for this article do not establish a categorical requirement for a life-care planner. The focus is on the opinions offered, the witness’s issue-specific qualifications, and the foundation for provider recommendations, frequency, duration, and pricing assumptions. A planner qualified to coordinate and price supported care is not automatically qualified to originate a medical-necessity opinion.

Can current medical bills prove what future treatment will cost?

They may help provide a reasonable basis for cost. By themselves, however, they do not establish that future treatment is caused by the injury, will probably be necessary, or will occur at a stated frequency and duration.

Are future medical expenses reduced to present value in Washington?

WPI 34.02 measures future economic awards by present cash value—the amount now that, invested at a reasonable return, will fund supported expenses when due. Giving that instruction requires evidence of an appropriate rate and calculation guidance. That is an evidentiary requirement, not an option for the claimant to choose whether to discount. No single method is mandatory, and supported inflation assumptions may matter.

Questions About Future Medical Costs in a Washington Claim?

The strength of a future-medical-cost projection depends on the individual medical record, the care being claimed, the witnesses offering opinions, and the foundation for each assumption. Vancouver and Clark County claimants who want help understanding how those issues may fit their circumstances can learn more about Vancouver and Clark County personal-injury help.

This article is for educational information only. It is not legal advice and does not predict whether particular evidence will be admitted or whether any person will recover future medical expenses.

Source Notes

Research cutoff: September 9, 2026. The legal principles in this article are based on the following Washington authorities and guidance:

Taylor v. Lubetich, 2 Wn.2d 6, 97 P.2d 142 (1939) — reasonably certain future medical attention.
Leak v. U.S. Rubber Co., 9 Wn. App. 98, 511 P.2d 88 (1973) — probability, causation, limited-duration future care, and the distinction between proving a loss and estimating its amount.
Erdman v. Lower Yakima Valley, Washington Lodge No. 2112 of B.P.O.E., 41 Wn. App. 197, 704 P.2d 150 (1985) — inferences from a sufficiently developed record and reasonable estimation of future care.
Stevens v. Gordon, 118 Wn. App. 43, 74 P.3d 653 (2003) — record-specific testimony supporting probable future care and cost.
Moore v. Smith, 89 Wn.2d 932, 578 P.2d 26 (1978) — the general damages-estimation principle after existence of loss is established; not itself a future-medical-expense case.
Patterson v. Horton, 84 Wn. App. 531, 929 P.2d 1125 (1997) — narrow use of medical records and bills as support for future cost.
Washington Evidence Rule 702 and Evidence Rule 703 — expert qualifications, helpfulness, and opinion foundation.
Johnston-Forbes v. Matsunaga, 181 Wn.2d 346, 333 P.3d 388 (2014) — issue-specific qualifications, helpfulness, and adequate foundation and scope.
Frausto v. Yakima HMA, LLC, 188 Wn.2d 227, 393 P.3d 776 (2017) — ARNP medical-causation testimony subject to issue-specific ER 702 qualification; reversal and remand, not automatic qualification.
Mendelsohn v. Anderson, 26 Wn. App. 933, 939–40, 614 P.2d 693 (1980) and Snow v. Whitney-Fidalgo Seafoods, Inc., 38 Wn. App. 220, 686 P.2d 1090 (1984) — evidentiary support for a present-value instruction; the cited Mendelsohn discussion is in the majority, not the dissent beginning at page 941.
Cornejo v. State, 57 Wn. App. 314, 788 P.2d 554 (1990) — annuity evidence as one permissible present-value method when the testimony satisfies ER 702 and ER 703.
Washington Pattern Jury Instructions: Civil, WPI 30.07.02 and WPI 34.02 — nonbinding committee guidance concerning future medical expenses and present cash value.

Authorities should receive a current-law check before reliance in a particular matter; this article does not provide an exhaustive citator review.