Over the past four fiscal years, FedEx (NYSE:FDX) has posted stellar earnings growth, as its multiyear profit improvement program has gained traction. This has lifted the stock from less than $100 in mid-2013 to around $210 by the end of last week.

However, FedEx has missed analysts' earnings estimates for two straight quarters, including a rare earnings decline in its most recently reported quarter. The company is scheduled to release its fourth-fiscal-quarter earnings report on Tuesday afternoon. Management has built up big expectations for this earnings report that FedEx will have to try to live up to.

Aggressive guidance

FedEx got off to a blistering start in fiscal year 2017, as earnings per share soared 20% year over year during the first quarter. Following that strong performance, management forecast that adjusted EPS would reach $11.85 to $12.35 for the full year, up from $10.80 a year earlier.

However, year-over-year growth in adjusted EPS slowed to 9% in Q2 and adjusted EPS fell 6% year over year in Q3. As a result, FedEx needs to post a 15% increase in adjusted EPS this quarter just to reach the low end of its full-year guidance range. To hit the high end of the range, it would need a 30% increase.

A FedEx Express airplane flying above the clouds.

FedEx's management has forecast strong EPS growth for Q4. Image source: FedEx.

As of three months ago, FedEx's management remained confident about hitting the full-year guidance. The company faced a significant year-over-year earnings headwind in Q3 related to the timing of when it passes fuel cost increases through to customers. That probably turned into a tailwind last quarter, which could enable big earnings increases for FedEx's express and ground delivery segments.

Even so, FedEx has little chance of reaching the upper part of its guidance range. Even the most bullish analyst on Wall Street expects the company's full-year adjusted EPS to come in right at the midpoint of the guidance range -- $12.10.

Ignore the pension adjustments

Two years ago, FedEx adopted "mark-to-market accounting" for its pension plans. This means that at the end of each fiscal year, it recognizes gains and losses related to changes in assumptions about interest rates and life expectancy. (By contrast, most companies defer these gains and losses and spread out the impact on their earnings over a period of many years.)

Due to this accounting change, FedEx's fourth-quarter earnings report is likely to include a big gain or a big loss related to the company's pension plan.

Investors shouldn't pay much attention to the pension adjustment, though. Any gains or losses reported this week could be reversed (or increased) at this time next year. The ultimate cost of FedEx's pension plans depends upon the future investment returns of the plan assets and the lifespan of plan participants.

What's the forecast?

The stakes are high for FedEx's fourth-quarter earnings report, as investors are looking for a return to strong earnings growth following two disappointing quarters. However, the company's forecast for 2018 will be equally important.

FedEx is projecting that operating profit for the combined express business (including TNT Express, a rival package delivery company acquired last year) will rise by $1.2 billion to $1.5 billion by fiscal year 2020. This will come from merger synergies as well as a continuation of both companies' profit improvement plans.

As a result, investors expect FedEx's earnings growth to accelerate again beginning in fiscal year 2018. The average analyst estimate calls for 14% EPS growth in the coming fiscal year. For FedEx stock to continue gaining ground after more than doubling in the past four years, the company will have to show that this expected uptick in earnings growth is on the way.

Check back on Tuesday evening for full coverage of FedEx's fourth-quarter earnings report.