Guide · Workplace · Illinois

TTD, PPD, and MMI: Workers’ Comp Benefits in Plain English

The initials on your comp paperwork decide how much reaches your household and for how long. Here is what each one means, and where money gets lost.

By Lincoln Square Law · 8-minute read

Workers’ compensation paperwork is full of initials. TTD, TPD, AWW, MMI, PPD. They look like administrative shorthand, but each one controls money: how much reaches your household each week, for how long, and what you receive when treatment ends. This guide explains the main benefit types under the Illinois Workers’ Compensation Act, how they are calculated, and where injured workers most often lose money without realizing it.

AWW: the number everything is built on

Most wage-based benefits are calculated from your average weekly wage, usually abbreviated AWW. The Act defines it by reference to your earnings in the 52 weeks before the injury, with rules for shorter periods of employment and for gaps in work (820 ILCS 305/10). Overtime, second jobs, and other earnings can affect the figure depending on how they were paid and whether they were regular.

An AWW that is too low reduces every weekly check and the value of permanent benefits later. It is worth checking the calculation against your pay stubs early. Errors are common, and they are much easier to correct at the start than after months of payments.

TTD: temporary total disability

Temporary total disability benefits are paid while you are unable to work at all because of the injury, or while your doctor has restricted you and the employer has no suitable work within those restrictions. TTD is generally two-thirds of your AWW, subject to minimum and maximum weekly rates set under the Act and adjusted periodically (820 ILCS 305/8(b)). There is a short waiting period at the start. Benefits are not paid for the first three working days of lost time unless the disability lasts long enough to make them payable back to the first day.

TTD continues until you return to work, are released to work you can actually be offered, or reach maximum medical improvement. The Illinois Supreme Court has held that the critical question is whether the worker’s condition has stabilized, and that an employer’s decision to discharge the worker does not by itself end the obligation to pay TTD before that point (Interstate Scaffolding, Inc. v. Illinois Workers’ Compensation Comm’n, 236 Ill. 2d 132 (2010)).

TPD: temporary partial disability

When you return to light duty at reduced hours or reduced pay while still healing, the Act provides temporary partial disability benefits to make up part of the difference, generally two-thirds of the gap between your pre-injury average weekly earnings and what you earn in the light-duty job (820 ILCS 305/8(a)). TPD is frequently overlooked. If your light-duty paychecks are smaller than your old ones, ask whether TPD is being paid.

MMI: maximum medical improvement

MMI is not a benefit. It is a medical milestone: the point at which your condition has stabilized and further treatment is not expected to produce significant improvement. Reaching MMI usually ends TTD and shifts the case toward permanent benefits. It does not necessarily mean you are healed, and it does not end your right to reasonable and necessary medical care related to the injury (820 ILCS 305/8(a)).

Because MMI changes the benefit picture, disputes over when it occurred are common. An insurer’s examining doctor may declare MMI earlier than your treating physician would. Your treating doctor’s opinion, and the records supporting it, are important evidence on that question.

Medical care and your choice of doctor

Medical benefits are separate from wage benefits and are often the most valuable part of a claim. The employer is responsible for reasonable and necessary medical care to cure or relieve the effects of the injury (820 ILCS 305/8(a)). The Act also lets you choose your treating doctors, within limits: you generally have two choices of physician, plus the specialists and providers those doctors refer you to. If your employer has a preferred provider program approved under the Act, declining it can count as one of your choices. Emergency care does not use up a choice.

Those limits matter in practice. Changing doctors casually can use up choices you may need later, and treating outside the chain of referrals can leave bills unpaid. Before switching providers, confirm how the change will be counted, and make sure each doctor’s notes describe your restrictions clearly, because those notes drive TTD, TPD, and light-duty decisions.

PPD: permanent partial disability

If the injury leaves a lasting impairment, the Act provides permanent partial disability compensation. There are several ways it is measured:

• Scheduled losses. Injuries to specified body parts, such as a hand, arm, leg, foot, eye, or finger, are compensated as a percentage loss of use of that part, multiplied by a number of weeks set in the statutory schedule (820 ILCS 305/8(e)).
• Person as a whole. Injuries not on the schedule, such as many back and neck injuries, are compensated as a percentage of the person as a whole, measured against a statutory number of weeks (820 ILCS 305/8(d)2).
• Wage differential. When the injury forces you into lower-paying work, you may elect a wage-differential award based on two-thirds of the difference between what you could earn before and what you can earn after (820 ILCS 305/8(d)1).

Since 2011, the Commission must consider five factors in determining permanent partial disability:

• an impairment rating prepared under the AMA Guides, if one exists
• your occupation
• your age at the time of injury
• your future earning capacity
• evidence of disability in the treating medical records

No single factor is determinative (820 ILCS 305/8.1b). The impairment rating is often obtained by the employer, and it is not the final word.

PTD and other benefits

If the injury leaves you permanently unable to work in any regular employment, permanent total disability benefits may be available (820 ILCS 305/8(f)). The Act also provides for vocational rehabilitation and maintenance benefits in appropriate cases, and for death benefits to dependents when a work injury is fatal.

When payments are late or stop

Benefits sometimes stop abruptly after an insurer’s examination, a surveillance video, or a disputed light-duty offer. Payments may also arrive late or short. The Act provides penalties and attorney’s fees for unreasonable or vexatious delay or refusal to pay, and additional compensation for late payment without good cause (820 ILCS 305/19(k) and 19(l), 820 ILCS 305/16). Those remedies must be pursued before the Commission, and documentation of every payment and every missed payment is the foundation for them.

Settlements

Many comp cases end in a settlement contract rather than a hearing decision. Settlements must be approved by the Commission, and they often resolve permanent disability, and sometimes future medical rights, in exchange for a lump sum. Before signing, it is important to understand what is being given up, particularly any waiver of future medical care, how the amount compares with the likely PPD award, and whether other benefits or a third-party claim are affected.

Where money gets lost

• An AWW that leaves out regular overtime or concurrent earnings.
• Light-duty wages with no TPD paid for the difference.
• TTD stopped after an early MMI opinion that the treating doctor disputes.
• A quick PPD settlement accepted before the impairment is fully understood.
• A third-party claim against someone other than the employer that nobody investigated.

Deadlines

You must notify your employer of the accident as soon as practicable, and not later than 45 days after it (820 ILCS 305/6(c)). An application for adjustment of claim generally must be filed with the Commission within three years after the accident, or within two years after the last payment of compensation, whichever is later (820 ILCS 305/6(d)).

Keep copies of every check stub, medical note, and work restriction. In a comp case, the paperwork is the case, and small errors compound over the life of the claim.